Last update: 2021/12/17 00:00
d2:laser_controller https://www.vescent.com/manuals/doku.php?id=d2:laser_controller
https://www.vescent.com/manuals/
Printed on 2021/12/18 07:41
laser housing, the housing must be electrically insulated
from ground.
The laser current is output through an SMA connector and returns through the cable shielding to
ground.
Temperature Control
Power (LED indicator)
All electronic modules have a blue LED power indicator on the top right side of the front panel control
section. The LED re15V and 5V in order to light.
Temp Status (dual LED indicators)
The temperature status LED indicators turn red whenever the temperature servo loop has been
disengaged. The temperature servo loop will disengage when the temperature is below -1°C, above
50°C, or the thermistor is shorted or open. Additionally, when the TEMP LOCK is in standby mode, the
servo loop is off and the LED's will be red.
The temperature status LED indicators will turn green when the temperature is within a narrow
temperature window of the setpoint. The window is typically set to a 100mK for stage 2 and 500mK
for stage 1 and can be monitored via T4 on the side-panel.
T2 Set (Trimpot)
The temperature of the laser diode (T2) is set with a front panel trimpot. When a D2-100 laser is
purchased with the controller, T2 is factory set to put the laser at the requested wavelength, typically
resonant with hyperfine transitions, and should not need trimming. However, as the diode ages the
user might need to adjust this value. Set the display selector knob to read T2
set
and set to the desired
value. Note: Before attempting to set the set point temperature, you must connect a thermal plant to
the D2-105. If you do not have a plant attached to the temperature loop, the set point range will
appear to be limited to less than ~12°C.
T1 is also set at the factory and should not require further adjustment. However, the T1 trimpot can
be accessed by removing the right panel from the enclosure. Note: Before attempting to set the set
point temperature, you must connect a thermal plant to the D2-105. If you do not have a plant
attached to the temperature loop, the set point range will appear to be limited to less than ~12°C.
Temp Lock (Dual position switch)
The temperature servo can be placed into standby mode if desired. In this mode no current is
supplied to the TEC elements.
Temp Servo Input (BNC)
The temperature servo input is summed to the T2 temperature set point signal and can be used to
make electronic perturbations to the laser diode temperature. The Temp Servo Input, has two
settings: “Low” and “High” gain. The default settings is “Low” but can be changed by a switch
accessible on the right side panel. See
.
