Operating The Laser Current Source From The Front Panel - Newport LDC-3706 Series User Manual

Operating the Laser Current Source from the Front Panel

This section describes fundamentals of operation for the LDC-3706 Laser Controller Laser Current
Source in two operating modes, Constant Current (I), and Constant Power (P). The current mode of
operation is indicated by a lit LED next to the mode of operation in use in the Laser Mode section of
the front panel. The mode of operation may be adjusted using the Select (right) button in this section
of the front panel.
Operating a Laser in Constant Current (Current) Mode
1. Plug the LDC-3706 into an appropriate AC power source supplying the correct mains voltage
and frequency for the instrument (refer to the rear panel for the correct ratings)
2. Turn on the LDC-3706. The laser output will be disabled at power up and the unit will
automatically configure its parameters to the state which existed when the power was last
shut off.
3. If the temperature controller is required please refer to the section below on temperature
control prior to enabling the laser current output.
4. Press the LASER MODE soft button until the CURRENT LED is illuminated.
5. Select the maximum output current range for the laser by pressing the RANGE soft button
under LASER RANGE. For best performance select the lowest range that allows the laser to
be run at the maximum desired output current.
6. Press LASER under PARAMETER to adjust the laser current limit, voltage limit, power limit
(if applicable), calibration PD value, photodiode reverse voltage bias, and LD TEC error link.
Note: For best low noise operation the modulation frequency bandwidth should be set to LOW and the MOD LED
should be turned off and the LNF-320 Low Noise Filter should be installed on the back of the instrument, if
available.
7. Under the ADJUST section press the LASER soft button and use the knob to adjust the
output current to the desired output. Press the ON soft button under LASER MODE. It is
advised when using a new laser or connection to the laser to set the output to zero prior to
enabling the output. Once the output is enabled slowly ramp the current to the desired
output.
8. The user can display measured voltage, photodiode current, calculated photodiode power,
and current setpoint on either the left or right side of the LASER display by pressing the
LEFT or RIGHT display soft buttons under the LASER display.
December 2019 27 LDC-3706 Series Laser Controller