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Keysight N4372E User Manual

Lightwave component analyzer
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Keysight N4372E
Lightwave Component
Analyzer
User's Guide

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  • Page 1 Keysight N4372E Lightwave Component Analyzer User's Guide...
  • Page 2 THE IMPLIED WARRANTIES OF sight.com/find/sweula. The license set MERCHANTABILITY AND FITNESS FOR A forth in the EULA represents the exclusive PARTICULAR PURPOSE. KEYSIGHT SHALL authority by which the U.S. government Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 3: Table Of Contents

    Preparing the Network Analyzer Setting up the Lightwave Component Analyzer 3 Performance Quick Check Preparation Network analyzer settings and electrical calibration Verifying your Electrical Calibration Verifying the Optical Connections and Optical CW Operation Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 4 Initializing the EO measurement Making single-ended EO measurements Making differential EO measurements Returning to Electrical Measurements Measuring Optical-Optical (OO) Devices Initializing the OO measurement Making OO measurements Aborting a Measurement Measuring Optical Power Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 5 EO measurements (lasers, modulators) OE measurements (photodiodes) OO measurements Signal Relationships in Opto-Electric Devices Single-Ended Measurements Differential Measurements (applies to 4-port PNA only) Differential OE measurements Differential EO measurements Differential results Calibration Concept Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 6 How to clean instruments with a recessed lens interface How to clean optical devices which are sensitive to mechanical stress and pressure 8 Troubleshooting Checking the Operation of the Lightwave Component Analyzer Event Log Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 7 Characteristics and Specifications Declaration of Conformity 12 Regulatory and Warranty Information Regulatory Information Declaration of Conformity Warranty System Remove all doubt Keysight E-mail Updates myKeysight Keysight Open Phone or Fax Keysight Online Information Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 9 Keysight N4372E Lightwave Component Analyzer User's Guide Introduction / 10 Documentation / 10 General Safety Considerations / 19 Optical Test Set Front and Rear Panels...

  • Page 10: Documentation

    Introduction Documentation The documentation for the Keysight N4372E Lightwave Component Analyzer (LCA) consists of the following: • The documentation for the Keysight network analyzer. This documentation is on the hard disk of the network analyzer. Refer to it for using the network analyzer for electrical to electrical measurements, or for the configuration of the network analyzer.

  • Page 11: Instrument Markings

    If this product is not used as specified, the protection provided by the WARNING equipment could be impaired. This product must be used in a normal condition (in which all means for protection are intact) only. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 12 4 °C for every 100 watts dissipated in the cabinet. If the total power dissipated in the cabinet is greater than 800 watts, then forced convection must be used. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 13 This instrument has autoranging line voltage input. Be sure the supply CAUTION voltage is within the specified range. The Keysight N4372E Lightwave Component Analyzer (LCA) complies CAUTION with over-voltage category II and can operate from the single-phase AC power source that supplies between 100 V and 240 V at a frequency in the range 50 to 60 Hz.

  • Page 14: Line Power Connectors

    Keysight Technologies Service Center. Do not operate the instrument in the presence of flammable gases or fumes. Operation of any electrical instrument in such an environment constitutes a definite safety hazard. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 15: Laser Safety Information

    The use of optical instruments with this product will increase eye hazard. The laser module has a built-in safety circuitry which will disable the optical output in the case of a fault condition. Refer servicing only to qualified and authorized personnel. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 16 Laser class according to IEC 60825-1:2014 Max. permissible CW output power 300 mW 163 mW * Max. CW output power is defined as the highest possible optical power that the laser source can produce at its output connector. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 17: Laser Safety Labels

    IEC 60825-1:2014, we recommend that you stick the laser safety labels, in your language, onto a suitable location on the outside of the instrument where they are clearly visible to anyone using the instrument. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 18: Laser Safety Symbols

    WEEE Directive Annex I, this product is classed as a "Monitoring and Control instrumentation" product. Do not dispose in domestic household waste. To return unwanted products, contact your local Keysight office, or see http://about.keysight.com/en/companyinfo/environment/takeback.shtml for more information. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 19: Optical Test Set Front And Rear Panels

    Turns on the LCA Test Set Controller. Optical Input of LCA Optical Receiver Input port for the optical signal from the device under test. CAUTION: Do not apply more than +14 dBm (maximum safe average input power). Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 20 Depending on the S parameters of the measurement, this can be either an RF input or an RF output. 1mm rugged RF adapter Connects port A/B of the LCA Optical Transmitter/Receiver to the network analyzer. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 21 The software on the network analyzer uses the USB port to control the LCA Test Set Controller. Line power cable connector Plug in your power cable here. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 23 Keysight N4372E Lightwave Component Analyzer User's Guide Setting Up the Instrument / 24 Unpacking the Lightwave Component Analyzer / 27 Mounting the Test Set and the Network Analyzer / 35 Setting up the Lightwave Component Analyzer...

  • Page 24: Unpacking The Lightwave Component Analyzer

    N4372-67984/N4372-67985 LCA Optical Receiver 100 GHz/110 • 5067-1395 f-f Adapter 1.0 mm • -021 straight connector • 1x N4373-87907 Patchcord SMF APC-PC 0.5 m • 1x 1005-0256 Feed-Thru • 1x 08154-61723 Connector Adapter FC Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 25 -IK4 Interconnect Kit for 4 Port PNA with 2.4 mm or 1.85 mm Ports • N5292-60017 • Mounting Kit • 2x 2x 0403-1166 Adjustable Foot 65.0 mm • 6x 0515-0433 Screw Torx-T20 M4X0.7 8mm • 20x 0515-1269 Screw Torx-T20 M4X0.7 10mm Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 26 1x N4373-25291 Bracket Rear Left Refer also to the contents list of the network analyzer. If anything is missing or defective, contact your nearest Keysight Technologies sales office. If the shipment was damaged, contact the carrier, then contact the nearest Keysight Technologies sales office.

  • Page 27: Mounting The Test Set And The Network Analyzer

    Millimeter Wave Network Analyzer System. The Millimeter Wave Network Analyzer System and the LCA Test Set CAUTION Controller can be assembled as one analyzer unit. Lifting this instrument requires two people using proper lifting techniques. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 28: Preparing The Lca Test Set Controller

    N4373-25271 to the rear side of the test head. Use the screws 0515-0433 and a Torx T20 screwdriver to attach the brackets N4373-25290 and N4373-25291 to the right and left bracket adapter. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 29 Turn the test head on its side and use a Pozidrive size 2 screwdriver to mount the adjustable feet 0403-1166 to the left and right brackets. Turn the test head back to its normal position. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 30 Setting Up the Instrument Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 31: Preparing The Network Analyzer

    Preparing the Network Analyzer Unlock all four feet of the Millimeter Wave Network Analyzer System to remove them from the bottom. It is recommended to perform this step with at least two, better three, persons. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 32 Place the Millimeter Wave Network Analyzer System on top of the LCA Test Set Controller and align it with the mounting slots of the rear brackets. It is recommended to perform this step with at least two, better three, persons. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 33 Millimeter Wave Network Analyzer System and left and right rear brackets. Use a Torx T20 screwdriver to attach the side bars N4372-21214 with the screws 0515-1269 to the left and right of the two instruments. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 34 Attach the adhesive trim covers to the left- and right-side bars to cover the screws (optional). Use a 13mm wrench to level the adjustable feet to the other feet of the test head. Use the upper nuts to lock the feet in place. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 35: Setting Up The Lightwave Component Analyzer

    Repeat steps 2 – 6 to connect the LCA Optical Transmitter with the network analyzer. The 1.0mm rugged RF adapter are part of the calibration for the LCA NOTE Optical Transmitter/Receiver. Do not change or lose them. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 36 Transmitter. This might irreversibly damage the LCA Optical Transmitter. Remove the dust cap from the optical output. 10 Remove the dust caps from the SMF optical patch cord (Option 021: N4373-87907, Option 022: N4373-87906). Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 37 16 On the rear, connect the network analyzer to the LCA Test Set Controller using the supplied USB cable. 17 Connect the power cables. 18 Continue with Performance Quick Check on page 39 or Starting the Lightwave Component Analyzer on page 50. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 38 Setting Up the Instrument Figure 5 USB-connection between the LCA Test Set Controller and the Network Analyzer Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 39 Verifying the Optical Connections and Optical CW Operation / 46 Verifying the Electrical Connection and Electro-optical Operation This chapter shows how to: • Verify the optical and electrical connections to the N4372E Lightwave Component Analyzer. • Verify the performance of your N4372E Lightwave Component Analyzer.

  • Page 40: Preparation

    Make sure the LCA has been returned to the electrical measurement mode as described in Returning to Electrical Measurements page 69. To meet the technical specifications, you must use the calibration kit. NOTE Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 41: Verifying Your Electrical Calibration

    If the results differ from the expected values, do the following: • Visually inspect all RF connectors. If an electrical connector seems to be damaged, contact Keysight for repair or replacement. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 42: Verifying The Optical Connections And Optical Cw Operation

    Use the FC/APC through adapter (1005-1027) to connect the ends of the optical patch cords. Press the [Macro/Local] utility button until the Macro 1 group is highlighted and you see Press to start the LCA measurement setup. Select the OO measurement tab. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 43 The readout should be +3 dBm ± 0. 5 dB. 10 Press the [Macro/Local] utility button until the Macro 1 group is highlighted and you see 11 Press to start the LCA measurement setup. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 44: 13 Set The Following Parameters

    1310 nm or 1550 nm wavelength and known output power, and input of the LCA Optical Receiver. Note that the angled connector must be attached to the optical test set. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 45: 19 Press The [Macro/Local] Utility Button Until The Macro 1 Group Is

    With the laser switched off, inspect all optical connectors with a microscope. • If the connectors on the N4373E Lightwave Component Analyzer seem to be damaged contact Keysight for repair. • If the connectors on the patch cord seem to be damaged contact Keysight for replacements.

  • Page 46: Verifying The Electrical Connection And Electro-Optical Operation

    Lightwave Component Analyzer test set. Press the [Macro/Local] utility button until the Macro 1 group is highlighted and you see Press to start the LCA measurement setup. Select the OO measurement tab. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 47 10 Right click the measurement trace, and select “Autoscale All” in the context menu. At the end of the measurement, there should be a flat trace. An ideal trace might look like this: Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 48 Inspect the electrical connectors on the N4372E Lightwave Component Analyzer and on the ruggedized 1.0 mm (f) to ruggedized 1.0 mm (f) adapter visually. If electrical connectors seem to be damaged, contact Keysight for repair or replacement. • Clean the electrical connectors on the N4372E Lightwave Component Analyzer and on the ruggedized 1.0 mm (f) to...

  • Page 49: Making Measurements

    Keysight N4372E Lightwave Component Analyzer User's Guide Making Measurements / 50 Starting the Lightwave Component Analyzer / 50 Calibrating the Network Analyzer before Measurements / 54 Measuring Opto-Electrical (OE) devices / 64 Measuring Electro-Optical (EO) Devices / 69 Returning to Electrical Measurements...

  • Page 50: Starting The Lightwave Component Analyzer

    After completing the electrical calibration, do not alter the IF bandwidth, start frequency, stop frequency, measurement point number or other settings. You may get measurement errors if you change any of those parameters. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 51: Electrical Calibration For Single-Ended Measurements

    It is recommended to use the 6 mm and 14 mm torque wrenches NOTE (Keysight part number 8710-2812 and 8710-2813, 45 N-cm/4 lb-in) and a 12mm wrench to tighten all RF connections during the calibration. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 52: Electrical Calibration For Differential Oe Measurements

    Electrical calibration for differential OE measurements To ensure the specified performance of the LCA, you should perform a full three- port electrical calibration. See the Keysight website for applicable calibration kits. If you want to perform an OE user calibration (see page 61 for details), we...

  • Page 53: Electrical Calibration For Differential Eo Measurements

    Select DUT connectors and the Cal Kits (e.g. “1.0mm female” and “85059B”). Follow the instructions for further steps shown on the Network Analyzer. After the calibration has been completed, save the calibration file for later reuse. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 54: Measuring Opto-Electrical (Oe) Devices

    PNA only) on page 104. Before you make your first opto-electrical measurement, you must initialize the OE measurement. You can see which measurement is currently initialized at the top left of the trace screen. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 55: Initializing The Oe Measurement

    Please refer to the user’s guide and online help of the network analyzer for further information. Initializing the OE measurement Press Select the “OE Measurement” tab. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 56 Note that, optimizing every sweep adds about 1 second to each measurement. "Continuous" modulator bias optimization superimposes a 10 kHz pilot tone onto the signal. This improves the short and long term stability of the modulator operating point. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 57 If you need to deembed optical components, such as attenuators, fiber optic cables or splitters, located between the laser output and your device under test, open and enable the “Optical Path Deembedding”. Here you can enter the parameters of the optical path directly. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 58 Making Measurements If you already have an .s2p file for your device, set "Deembedding Data" to "File" and enter or select the .s2p file name. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 59 So for improved results at lower frequencies, select “Measure”. • If you want to reuse an existing user calibration, select “Load”, and select the calibration file from the Windows Explorer window. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 60 Afterwards the LCA returns to the currently activated electrical calibration for the DUT measurements. The currently activated electrical calibration is preselected in the "CalSet for User Calibration" combo box. This preselection is fine Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 61 The default bandwidth reduction factor is defined in the LCAConfig.xml file. c Click to proceed. d Choose whether you want to save the calibration data for later use. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 62: Making Single-Ended Oe Measurements

    When the following message is displayed, click "Single" or "Continuous" to start the first measurement. To make further measurements with these settings, press to start the measurement. For information on further parameters, refer to User Interface Reference page 77. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 63: Making Differential Oe Measurements (Applies To 4-Port Pna Only)

    When the following message is displayed, select "Single" or "Continuous" to start the first measurement: To make further measurements with these settings, press click to start the measurement. For information on further parameters, refer to User Interface Reference page 77. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 64: Measuring Electro-Optical (Eo) Devices

    85. Before you make your first electro-optical measurement, you must switch to EO measurement mode. You can see which measurement is currently initialized at the top left of the trace screen. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 65: Initializing The Eo Measurement

    Graphical user interface of the LCA software On a 4-port LCA, select Differential or Single-Ended Measure Mode, depending on the type of your DUT. Select or enter the wavelength at which you are testing. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 66 If you are using a 75 Ohm minimum loss pad, enable the RF Path Deembedding, and make sure 75 Ohm is selected. Enter or select the file with the characterization of the minimum loss pad. Click to start the measurement preparation. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 67: Making Single-Ended Eo Measurements

    "Continuous" to start the first measurement. Figure 11 Window to trigger LCA measurements To make further measurements with these settings, press to start the measurement. For information on further parameters, refer to User Interface Reference page 77. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 68: Making Differential Eo Measurements

    “Continuous” to start the first measurement. Figure 13 Window to trigger LCA measurements To make further measurements with these settings, press to start the measurement. For information on further parameters, refer to User Interface Reference page 77. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 69: Returning To Electrical Measurements

    NOTE on the type of your network analyzer. See on page 90. RF Power Press Make sure the “EE Measurement” tab is selected. Figure 14 Graphical user interface of the LCA software Click Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 70: Measuring Optical-Optical (Oo) Devices

    If you have already initialized the OO measurement, you can connect your device under test and start the measurement by pressing Please refer to the user’s guide and online help of the network analyzer for further information. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 71: Initializing The Oo Measurement

    > 5 kHz. For IF bandwidth settings of the network analyzer > 10 kHz we recommend setting modulator bias optimization to "Every Sweep" or "Once". Not using “Continuous” modulator bias optimization affects Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 72 Here you can enter the parameters of the optical path directly. If you already have an .s2p file for your device, set "Deembedding Data" to "File" and enter or select the .s2p file name. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 73 Windows Explorer window. Optical and electrical path deembedding is not applied during a user NOTE calibration. Click to start the measurement preparation. If "User Calibration" mode is set to "Measure" the following screen is displayed: Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 74 The default bandwidth reduction factor is defined in the LCAConfig.xml file. c Click to proceed. d Choose whether you want to save the calibration data for later use. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 75: Making Oo Measurements

    When the following message is displayed, select "Single" or "Continuous" to start the first measurement. To make further measurements with these settings, press to start the measurement. For information on further parameters, please refer to User Interface Reference on page 77. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 76: Aborting A Measurement

    Select Input 2 as the Optical Input under Receiver on the “Tools” tab. Under Receiver on the “Tools” tab, specify the receiver wavelength. The optical power is also displayed at the bottom of LCA measurement NOTE setup screen. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 77: User Interface Reference

    Keysight N4372E Lightwave Component Analyzer User's Guide User Interface Reference / 78 The LCA Function Keys / 80 Default and Advanced Measurement Parameters / 80 Saving and Loading Setups / 82 The Measurement Parameters...

  • Page 78: The Lca Function Keys

    • : Start the optical power monitor. This uses the current measurement setup to determine the wavelength and the optical input for which the average optical power is measured. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 79 "Continuous" or "Single" button, since the network analyzer does not react to the keypad during measurements. In that case, abort the measurement with the "Abort Measurement" button in the LCA Server window. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 80: Default And Advanced Measurement Parameters

    The filename of the calibration data is saved with the setup, not the calibration data itself. For more details, see Measuring Opto-Electrical (OE) devices page 54 or Measuring Optical-Optical (OO) Devices on page 70. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 81: Loading Setups

    This is different to the behavior when doing OE or OO initialization without loading a setup. For more details, see Measuring Opto-Electrical (OE) devices page 54 or Measuring Optical-Optical (OO) Devices on page 70. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 82: The Measurement Parameters

    Measure Mode Figure 16 Graphical user interface of the LCA software A 2-port network analyzer can only support single-ended measurements. Selecting the Measure Mode is only possible if you have a 4-port network analyzer. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 83: Selecting Port Configuration

    If ‘Single-Ended’ measurement is selected, two columns are shown where you can select which port is connected to the source and which one is connected to the receiver. Figure 17 Single-Ended EO-measurement Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 84 Second differential port has the same or a lower port number than the first differential port. • The Receiver-port for the user calibration is the same as the port for the LCA Optical Transmitter. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 85: Differential

    • If you have selected to use the External Input, you can enter the wavelength of the external source here. This wavelength is used by the optical power meter. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 86: Optical Path Deembedding

    The value for the Refractive Index of a graded index multi-mode fiber is 1.49 for 62.5 μm at 850 nm, 1.475 for 50 μm at 850 nm and 1.465 for 50 μm at 1300 nm. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 87 All other parameters are ignored. To assign a file, Click at the right of the field to which you want to assign a file. Locate and select the file in the explorer window. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 88: Rf Path Deembedding

    The results need to be in the form of a 2-port S-parameter data file (also known as Touchstone .s2p data files). All the S-Parameters in the supplied file are used. Please note that 4-port S-parameter files (e.g. for differential probes) are currently not supported. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 89 Select if you measure components with 75 Ohm impedance. Insert the s2p file name for the file that characterizes the minimum loss pad. Figure 23 Graphical user interface of the LCA software with enabled RF path deembedding for 75Ohm Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 90: Tools

    Sets the RF power level for the receiver port(s). We recommend the factory calibrated default value for the best results. To reset to the factory default, leave the text box empty or enter a value less than -200 dBm. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 91: Reset Ui

    User Interface Reference Reset UI The Reset UI button resets all LCA settings to default settings. Figure 24 Tools-section of the LCA software Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 93: Measurement Concepts

    Signal Relationships in Opto-Electric Devices / 98 Single-Ended Measurements / 103 Differential Measurements (applies to 4-port PNA only) / 104 Triggering Concepts / 109 Measuring at Different Wavelengths and with the External Optical Source Input / 110 Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 94: General Measurement Techniques And Considerations

    Measurements are typically comprised of the appropriate ratio of microwave modulation current (or power) and lightwave modulation power. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 95 LCA Block Diagram Figure 25 demonstrates the basic concepts of lightwave component analysis. An analysis of how various signals are used in the measurement process is found in Signal Relationships in Opto-Electric Devices page 98. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 96: Eo Measurements (Lasers, Modulators)

    Graphically this is shown in the following figure. An LCA measures input modulating current and output modulation power and displays the ratio of the two in Watts/Amp, either linearly or in decibels. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 97: Oe Measurements (Photodiodes)

    As the lightwave component analyzer is able to measure amplitude and phase, dispersion measurements can be made with very high frequency resolution. This can be used to characterize narrow band optical components with a very high frequency resolution within the modulation bandwidth. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 98: Signal Relationships In Opto-Electric Devices

    S-parameters are used to describe the transmitted and reflected signal flow within a device or network. For the model, the following S-parameters are defined: where: Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 99 S-parameter definitions. Initially, the input impedance of the EO converter and the output impedance of the OE converter will be assumed to be Z (thus S and S are zero). Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 100 R and R It is convenient to express the transducer functions logarithmically in decibels. The system power gain from a Z source to a Z load can be defined using the above relationships: Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 101 Similarly, receiver conversion efficiency will be relative to 1 A/W. The individual responsivities can now be expressed individually in decibels: This now allows us to express the original equations for responsivity in logarithmic terms: Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 102 The measurement of modulation current is derived from the system characteristic impedance and a measurement of electrical power. The measurement of optical modulation power is based on a “standard” lightwave receiver whose characteristics are predetermined and known by the LCA. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 103: Single-Ended Measurements

    Single port measurements are made on devices when the signal on the electrical port is referenced to ground. This port is described by S-parameters. Figure 26 Single ended EO measurement Figure 27 Single ended OE measurement Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 104: Differential Measurements (Applies To 4-Port Pna Only)

    LCA test set. The physical ports 2 and 3 on the network analyzer connect to the differential electrical ports of the DUT. Figure 28 shows the physical setup for EO measurement and OE measurement, respectively. Figure 28 Differential EO measurement setup Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 105: Differential Oe Measurements

    For OE measurements the single- ended (SE), logical port 1 is assigned to physical port 1 and the balanced (BAL), logical port 2 is assigned to the physical ports 2 and 3 (see Figure 30 Figure 30 Logical Port Mapping for OE measurement Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 106: Differential Eo Measurements

    These include, differential responsivity S, common mode rejection or port imbalance. Since opto- electronic components are unidirectional, non-reciprocal devices, only the measurement types circled in Figure 32 are relevant. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 107: Calibration Concept

    The second stage is the calibration of the optical test set. This is handled as a “Fixture” by the network analyzer. For more information on Fixtures, please refer to the documentation of the network analyzer. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 108 Port A to the optical output, and from the optical input to the ruggedized 1.0 mm female to female adapter Port B, respectively. This electro-optical calibration is provided by Keysight, and includes the two Y1900D ruggedized 1.0 mm adapters supplied and connected to the optical test set.

  • Page 109: Triggering Concepts

    "Single", this time window is very short, since the LCA does nothing between the sweeps. In such cases, the running measurements can always be stopped by pressing the "Abort Measurement" button on the LCA Server window. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 110: Measuring At Different Wavelengths And With The External Optical Source Input

    2nd column for the optical input for each wavelength measured (i.e. both the internal and the additional wavelengths). Delete all other wavelength values. (Note: LCA interpolates for missing wavelengths.) Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 111: Eo Measurements

    Switch on your external source and run the modulator optimization in the "Default" mode. When the optimization is finished, transfer the optical power value displayed in the status bar to the "Power" box. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 112: Oo Measurements

    Definition of Terms OO measurements The principles described above for EO and OE measurements also apply to OO measurements. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 113: Maintenance

    Keysight N4372E Lightwave Component Analyzer User's Guide Maintenance / 114 Cleaning This system should be serviced only by authorized personnel. Using controls or adjustments or performing procedures other than WARNING those specified in the documentation supplied with your equipment can...

  • Page 114: Cleaning

    If you are unsure of the correct cleaning procedure for your optical device, we recommend that you first try cleaning a dummy or test device. Keysight Technologies assume no liability for the customer’s failure to comply with these requirements. Please follow the following safety rules: WARNING •...

  • Page 115: Why Is It Important To Clean Optical Devices

    • Compressed air Dust and shutter caps All of Keysight Technologies’ lightwave instruments are delivered with either laser shutter caps or dust caps on the lightwave adapter. Any cables come with covers to protect the cable ends from damage or contamination.
  • Page 116 Do not press the bottom of the cap onto the fiber too hard, as any dust in the cap can scratch or pollute your fiber surface. If you need further dust caps, please contact your nearest Keysight Technologies sales office. Isopropyl alcohol This solvent is usually available from any local pharmaceutical supplier or chemist's shop.
  • Page 117 The tip and center of the pipe cleaner are made of metal. Avoid accidentally pressing these metal parts against the inside of the device, as this can cause scratches. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 118: Additional Cleaning Equipment

    You can use a microscope to choose an appropriate cleaning method, and then to examine the results. You can also use your microscope to judge whether your optical device (such as a connector) is severely scratched and is, therefore, causing inaccurate measurements. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 119 Polymer film Polymer film is available from laboratory suppliers or specialist mail order companies. Using polymer film is a gentle method of cleaning extremely sensitive devices, such as reference reflectors and mirrors. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 120: Preserving Connectors

    Keep the caps on the equipment always when it is not in use. All of Keysight Technologies’ lightwave instruments and accessories are shipped with either laser shutter caps or dust caps. If you need additional or replacement dust caps, contact your nearest Keysight Technologies Sales/Service Office.

  • Page 121: Cleaning Instrument Housings

    • Use compressed air to blow away large particles. • Clean the device with a dry cotton swab. • Use compressed air to blow away any remaining filament left by the swab. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 122: How To Clean Connectors

    Use this procedure particularly when there is greasy dirt on the connector: Moisten a new cotton-swab with isopropyl alcohol. Clean the connector by rubbing the cotton-swab over the surface using a small circular movement. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 123: How To Clean Connector Interfaces

    Moisten a new cotton-swab with isopropyl alcohol. Using a new, dry pipe-cleaner, and a new, dry cotton-swab remove the alcohol, any dissolved sediment and dust. Blow away any remaining lint with compressed air. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 124: How To Clean Bare Fiber Adapters

    Rotate the pipe cleaner slowly as you do this. Clean the adapter by rubbing a new, dry cotton-swab over the surface using a small circular movement. Blow away any remaining lint with compressed air. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 125: How To Clean Lenses

    This is because it is difficult to remove any used alcohol or filaments from the input of the optical block. It is important, therefore, to keep dust caps on the equipment at all times, except when your optical device is in use. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 126: How To Clean Instruments With A Physical Contact Interface

    To assess the projection of the emitted light beam you can use an infrared sensor card. Hold the card approximately 5 cm from the interface. The invisible emitted light is projected onto the card and becomes visible as a small circular spot. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 127: How To Clean Instruments With A Recessed Lens Interface

    How to clean instruments with a recessed lens interface For instruments with a deeply recessed lens interface (for example the Keysight Technologies 81633A and 81634A Power Sensors) do not follow this procedure. Alcohol and compressed air could damage your lens even further.

  • Page 128: How To Clean Optical Devices Which Are Sensitive To Mechanical Stress And Pressure

    Put the film on the surface and wait at least 30 minutes to make sure that the film has had enough time to dry. Remove the film and any dirt with special adhesive tapes. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 129 Take a new soft tissue and moisten it with isopropyl alcohol. Carefully clean the bare fiber with this tissue. Make your cleave and immediately insert the fiber into your bare fiber adapter in order to protect the surface from dirt. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 131: Troubleshooting

    Keysight N4372E Lightwave Component Analyzer User's Guide Troubleshooting / 132 Checking the Operation of the Lightwave Component Analyzer This system should be serviced only by authorized personnel. Using controls or adjustments or performing procedures other than WARNING those specified in the documentation supplied with your equipment can...

  • Page 132: Checking The Operation Of The Lightwave Component Analyzer

    The log file is cleared each time the LCA server is restarted. If you have a problem with the LCA, you can also send the event log file to your Keysight contact person to speed up diagnosis. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 133 Keysight N4372E Lightwave Component Analyzer User's Guide Reinstalling and Updating the Software / 134 Backing Up your LCA Data / 134 Reinstalling the LCA Software...

  • Page 134: Backing Up Your Lca Data

    Select the LCA application from the list of programs. c Remove the program. Start the LCA setup software LCAInstaller.msi. Follow the instructions on the screen. We recommend you use the default settings. Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 135: Reinstalling The Lca Software

    Reinstalling and Updating the Software Reinstalling the LCA software Preparing the reinstallation. Download the LCA software from the Keysight website to a location on the network analyzer's "D" drive. Alternatively, copy the software installation file from the CD-ROM supplied with the LCA to the "D" drive, or run the software installation file directly from the CD-ROM using a USB-connected optical drive.
  • Page 137 Keysight N4372E Lightwave Component Analyzer User's Guide Definition of Terms / 138 Definition of Terms...

  • Page 138: Definition Of Terms

    The maximum difference between actual (true) Average output power (optical) and the nominal (selected) average output power. Conditions: After modulator auto bias (“modulator optimization”) performed with the selected wavelength. Other conditions as specified. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 139 NOTE “dBe” for electrical powers. : The square of the Responsivity R divided by 1 A/W, is defined correspondingly to dB Differences of responsivities in dB or dB are written as “dBe”. NOTE Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 140 Group delay uncertainty Specifies the maximum difference between measured and actual Group delay (GD). For E/O and O/E, group delay uncertainty excludes a constant group NOTE delay offset (see Phase uncertainty). Other conditions as specified. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 141 The amplitude of a harmonic optical power modulation. The modulated optical power is calculated from the peak optical power P and the average optical power P in Watts: P – P in dBm: P = 10-log(P / 1mW). mod,dB Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 142 Condition: modulation frequency as specified. OMI is a value between 0% (no modulation) and 100% (full modulation). NOTE Operating input wavelength range The wavelength range on the LCA optical input for which the LCA system is designed. Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 143 Changes in the cabling after user e-cal add to the specified relative NOTE frequency response uncertainty. Measurement: Based on a reference RF O/E receiver. Responsivity The amplitude response R of a device under test (DUT) to a harmonic stimulus: Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 144 Responsivity of an O/E or E/O device may be called conversion efficiency. NOTE For an O/O device, R [dBo] = -(insertion loss [dB]). References “Guide to the Expression of Uncertainty in Measurement” (“GUM”), BIPM, IEC, ISO et al. (1993) Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 145: Characteristics And Specifications Declaration Of Conformity

    User Interface Reference Characteristics and Specifications Characteristics and Specifications / 146 Declaration of Conformity / 146 Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 146 User Interface Reference Characteristics and Specifications For the characteristics and specifications of the N4372E, refer to the datasheet at: https://www.keysight.com/us/en/assets/3119-1065/data-sheets/5992-4 215.pdf Declaration of Conformity Declarations of Conformity for this product and for the Keysight products may be downloaded from the Web. Go to http://www.keysight.com/go/conformity.
  • Page 147 Keysight N4372E Lightwave Component Analyzer User's Guide Regulatory and Warranty Information / 148 Regulatory Information / 148 Declaration of Conformity / 149 Warranty / 150 Phone or Fax / 151 Keysight Online Information...

  • Page 148: Regulatory Information

    Cet appareil ISM est conforme à la norme NMB-001 du Canada. Acoustic Noise Emission LpA < 50 dB Operator position Normal operation per ISO 7779 Declaration of Conformity For latest DoC, please visit the web link: http://www.keysight.com/go/conformity Keysight N4372E Lightwave Component Analyzer User’s Guide...

  • Page 149: Warranty

    Remove all doubt Keysight offers a wide range of additional expert test and measurement services for your equipment, including initial start- up assistance onsite education and training, as well as design, system integration, and project management.

  • Page 150: Keysight Open

    Keysight Open simplifies the process of connecting and programming test systems to help engineers design, validate and manufacture electronic products. Keysight offers open connectivity for a broad range of system ready instruments, open industry software, PC-standard I/O and global support, which are combined to more easily integrate test system development.

  • Page 151: Keysight Online Information

    Optical test instruments accessories www.keysight.com/find/octaccessories Firmware and driver download www.keysight.com/find/octfirmware Keysight photonic discussion forum http://www.keysight.com/find/photonic_forum For Network analyzer related literature, please visit: Keysight Network Analyzers: www.keysight.com/find/na Mechanical and Electronic Calibration Kits: www.keysight.com/find/ecal RF Test Accessories, Cabinets, Cables: ww.keysight.com/find/accessories Keysight N4372E Lightwave Component Analyzer User’s Guide...
  • Page 152 This information is subject to change without notice. © Keysight Technologies 2020 Edition 1.0, April 2020 Printed in Germany www.keysight.com...

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