ExoMars UV Laser diode thermal vacuum test Alex Rousseau
Apr 01, 2015
ExoMars UV Laser diode thermal vacuum test
Alex Rousseau
Test setup
• Used ExoMars CCD test vacuum chamber. LN2 cooling with heaters backing off LN2.
• Fully automated thermal control system.• Rotary vacuum pumped chamber (5x10-3
mBar).• Photodiode fixed to chamber viewport to
measure UV laser diode output.• Temperatures and photodiode output logged
at 1 minute intervals.
Test equipment
Test setup (Cont.)
• UV laser diode assembly installed between two cold fingers and PID closed control loop temperature sensor installed on the laser diode mount (as close as possible to diode).
• Two temperature logging sensor installed on laser diode mount.
• Bench PSU connected through vacuum feed through for PCB V & I supply.
Laser diode installation in TV chamber
Test profile
• Cold non operational T: -150°C• Hot non operational T: +50°C• Hot operational T: +25°C• Cold operational T: ≥60°C
Test results – thermal profile
Test results – UV Laser diode output vs temperature
Test results – UV Laser diode output at test points
Test results – UV Laser diode temperature transition rates