THORLABS ULN15TK User Manual page 6

Ultra-Low-Noise Laser System
Operating the Laser
1. Please consult with your organization's laser safety officer regarding proper operation of the laser at your
institution.
2. It is highly recommended to secure the laser to an optical table or metal breadboard. This improves heat
dissipation from the laser housing and its long-term thermal stability. The laser housing includes two sets
of mounting holes (4x) designed for Imperial and Metric breadboards.
3. Ensure the interlock pin is fully installed
4. Connect the DC power supply (DS12) via the M8 connector on the back panel of the system. The Power
indicator on the front panel should be illuminated.
5. With power supplied, the ULN15TK system will immediately begin stabilizing the laser case temperature.
During laser case temperature stabilization, the Status indicator will blink. The system may require 1 - 2
minutes for basic thermal stability, during which time the laser cannot be turned on. When the laser case
temperature is stabilized, the Status indicator will turn off.
6. Connect any applicable modulation signals to the appropriate SMA modulation ports.
7. Remove the output fiber connector bulkhead cap and connect to the desired instrument using an
PM1550-XP FC/APC fiber patch cable.
8. The Laser is ready to be turned on and can be turned on by toggling the Enable push-button
indicator will blink for 5 seconds then remain solid at which point the laser emission is on. The laser
emission is not on during the blinking stage of the Emission indicator. Please note that the laser requires
a 10 minute warm-up time after it has been enabled in order to reach its specified linewidth.
9. Laser emission can be turned off with another toggle of the Enable push-button.
10. At any time, if the ULN15TK system detects a fault, the status indicator will light up solid and the laser will
be shut off.
11. To change the laser operating conditions, connect to the USB mini-B connector to configure settings for
the system. A list of commands and parameters are listed in Chapter 4 Software Communications.
External Modulation Ports
There are three modulation ports located on the front panel of the ULN15TK. Two ports are allocated for
modulating the current of the laser around the current set-point. The AC current modulation port is AC-coupled
and supports modulation frequencies from 2 kHz to 20 MHz. The DC current modulation port is DC-coupled and
supports frequencies from 0 Hz to 5 MHz. For both current modulation ports, an input voltage (-5 V to +5 V)
modulates the current at a rate of 2 mA/V around the current set-point. A third modulation port is included for
modulating the temperature of the laser around its set-point. Either the chip or the FBG temperature can be
controlled through the analog voltage input applied to this port (-5 V to +5 V). This port has a bandwidth of 1 Hz
and is designed for slow modulation of the laser temperature for applications that require locking the laser
frequency. The temperature modulation port is disabled by default and can be enabled to control either the chip
or the FBG temperature through a command sent via the USB or RS-485 connection on the back panel of the laser.
The rate of temperature change versus voltage can also be set through a command. Please see Chapter 5 for
a
An improperly installed interlock pin will not allow the laser to turn on, but will not be indicated as an error by the Error
indicator.
b
If the ULN system is powered on without the interlock pin, it must be power-cycled (unplugged from DC power supply and
reconnected) before the laser can be turned on.
c
For safety, a firm, deliberate button press is required.
Page 4
a,b
.
Chapter 3: Setup
c
. The Emission
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