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Daylight visibility of Laser Beam. Daylight Visibility of a kHz - but µJ – Laser Beam. Eastbourne , October 200 5. Hardware Setup. Video. Day/Night. Frame Grabber. Day/Night; 5 % of 532 nm. SensiCAM. (10 Hz & kHz; bigger FOV). ISIT-TV. Old CCD. Night only. Filter 0.3 nm.
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Daylight visibility of Laser Beam • Daylight Visibility • of a kHz • - but µJ – • Laser Beam Eastbourne, October 2005
Hardware Setup Video Day/Night Frame Grabber Day/Night;5 % of 532 nm SensiCAM (10 Hz & kHz; bigger FOV) ISIT-TV Old CCD Night only Filter 0.3 nm 95% of 532 nm 50 cm Main Telescope C-SPAD Dichroic Mirror Eastbourne, October 2005
SensiCAM - CCD • Problem: Backscatter of Single Shot TOO WEAK (400 µJ) • NOT Visible with CCD ... • Solution: Integrate Backscatter of 1000 Shots ... • But do NOT Integrate the noise between shots ! • => Increases Signal / Noise Ratio ! Laser Pulses 1000 Exposures 50 µs Exposure per Shot; Backscatter image only 1000 Shots integrated; needs 0.5 s / image @ 2 kHz Eastbourne, October 2005
CCD used in Graz • Sensicam 360KF; from PCO Imaging (www.pco.de) • Camera type: Interface type: PCI-Board 525 KP (Koax Version) • Programming: via the C++ Package included with the CCD; • Allows now for: • Continuous imaging of backscatter (no mirrors switched); • Uses only about 5% of the backscatter (leakage of dichroic mirror, which separates 532 from other wavelenghts); • Also used for rough visual adjustment of beam divergence ... • Future Plans: Automatic Detection of Laser Beam Peak • Automatic Beam Centering with Remote Controlled Mirror (manually adjusted now) Eastbourne, October 2005