Operating In Constant Current Mode; Figure 2.6 Constant Current Mode Setup, Laser - ILX Lightwave LDC-3926339 User Manual

Operating in Constant Current Mode

There are two constant current modes: low bandwidth (ILBW) and high bandwidth
(IHBW). The low bandwidth mode uses a low-pass filter on the laser drive current
output to reduce noise, while the high bandwidth mode bypasses this filter. Use
low bandwidth mode for CW operation or if the modulation frequency is below 27
kHz; use high bandwidth mode if the modulation frequency is above 27 kHz.
1
2
3
4
4a
4b
Note: Repeatedly pressing the INC/DEC keys or turning the Adjust Knob cycles through
the Constant Current low bandwidth (Ilbw), Constant Optical Power (P), Constant Current
high bandwidth (Ihbw), and Photodiode Current (Ipd) control modes.
5
5a
5b
5c
02_03
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
Press CHAN to display the channel menu. From this menu, you can see the measured
parameters.
Use the INC/DEC keys or the Adjust knob to select the desired channel number
highlighted at the top of the display.
Press the LAS soft key to enter page 1 of the laser channel setup menu.
From LAS page 1 menu, set the Current setpoint (Iset), the Current limit (Ilim), the Voltage
limit (Vlim), and the control mode (Mode). This page also displays measured current
output and laser forward voltage. You can also turn the controller on or off from this page.
Set the control mode.
Press NEXT until the Mode field is highlighted.
Select Ilbw or Ihbw using the INC/DEC keys or the Adjust knob.
Figure 2.6 Constant Current Mode Setup, Laser Page 1
Select the voltage limit (Vlim) and current limit (Ilim).
Press PREV to select the voltage limit (Vlim) parameter.
Using the Adjust Knob or the numeric keypad, set the Vlim value and press ENTER.
You must press Enter within three seconds of selecting the value.
Set the voltage limit slightly above the operating voltage of the laser diode to provide
maximum protection. The voltage limit protects your laser by shutting off the source driver
if the laser voltage exceeds the Vlim value.
Press PREV to select the current limit (Ilim) parameter.
O P E R A T I O N S
Operating from the Front Panel
2
C H A P T E R
15
LDC-3926339