Last update: 2021/03/02 17:06
d2:laser_servo https://www.vescent.com/manuals/doku.php?id=d2:laser_servo
https://www.vescent.com/manuals/
Printed on 2021/04/17 23:32
The AUXILIARY SERVO OUTPUT is generated from integrating the SERVO OUTPUT. Its purpose is to
supply a correction signal to drive the SERVO OUTPUT to zero. When used with Vescent DBR lasers
and the D2-105 Laser Controller, the AUXILIARY SERVO OUTPUT can be connected to the TEMP SERVO
IN to adjust the laser diode temperature to keep the feedback laser current constant. Similarly,
AUXILIARY SERVO OUTPUT can drive a PZT on an external-cavity laser diode to keep the laser diode
current constant. See
and
setting the gain and gain sign of the AUXILIARY SERVO OUTPUT.
Ramp Offset
The Ramp Offset provides the user with two front-panel knobs to adjust the voltage of the center of
the ramp. When the Ramp Offset is zeroed, the ramp is centered at 0 V and when the servo goes from
unlock mode to lock mode, it engages the integrators starting from 0 V. The user can adjust the Ramp
Offset knobs (coarse and fine) to define the center of the ramp and the initial voltage point from
which the servo begins integrating. The Ramp Offset is typically set to 0 V when Servoing Vescent
DBR lasers as this functionality is redundant with the current adjust knobs on the D2-105 Laser
Controller. Ramp Offset is more useful when servoing PZT-based external cavity lasers where the PZT
amplifier (if used) does not have an offset knob.
Ramp Offset Coarse
Coarse adjust to the center of the ramp signal and the DC Voltage output in UNLOCK mode. Range is
approximately ±5 V.
Ramp Offset Fine
Fine adjust to the center of the ramp signal and the DC Voltage output in UNLOCK mode.
Right Side Panel
Fig. 4: Side panel of D2-125 showing transfer function and
corner adjustments.
