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
SETPOINT ENABLE is a TTL input. 5 V puts the front panel dial in control of the injection current and 0
V gives control to SETPOINT IN.
When disconnected, the SETPOINT ENABLE is at 5 V.
The Servo Input on the front panel continues to function when the SETPOINT ENABLE is pulled low.
Only the Coarse and Fine Current Adjustments are disabled.
Turning on the Laser Diode
In compliance with FDA requirements for a Class 3B laser, the Laser Controller has two safety
interlocks. If either interlock is tripped, the laser will turn off and stay off until the interlocks are reset
AND the laser switch is switched from the “off / reset” position to the “on” position. Additionally, if the
Laser Controller loses power, the laser diode will remain off when power is restored.
To turn on the laser diode, follow these instructions:
Flip the Laser switch into “off/reset” position
Insert the key into the keyhole and rotate the key 90 degrees (keyhole located on back panel)
Place grounding BNC terminator on “Remote Interlock” BNC (located on back panel)
Flip the Laser switch into the “on” position. The green light above the switch should turn on and
after a 5 second delay, the laser will turn on.
Tuning the Temperature Controller
The range of pole settings for the T2 temperature control
loop (diode temperature control) for D2-105 Laser
Controllers with Serial Number 2675 and higher
(Temperature Control Board Serial Number 6987 and higher)
have been modified to allow the user to more easily control a
low thermal mass laser assembly such as a Photodigm TOSA.
Please use the appropriate instructions below for your Laser
Controller.
If you purchased the -FL option for your D2-105, then the T1
loop has the same available pole settings as the T2 loop of
controllers with Serial Number 2675 and higher.
If you purchased the Laser Controller with a Laser Module, then the Laser Controller is properly tuned
for the Laser Module's thermal load and you can skip this section. This section will describe the basic
theory about tuning the temperature servo response and provide step-by-step instructions for tuning
the servo response to your thermal load.
To get good temperature stability, the temperature servo response needs to be tuned to match the
thermal load. Access to tuning the temperature response is provided on the right side panel of the
Laser Controller and requires removing that side panel to access the controls. The Laser Controller
provides two independent temperature controllers that are nominally identical for models with S/N
2674 and below or PCBs with S/N 6986 or below and differ by a factor of 10 in their time constants for
models with S/N 2675 and above or PCBs with S/N 6897 or above. In either case, stage 2 has front
