2023-10-18 10am-3pm @ ATC North bldg, NAOJ
Yohei Nishino & Munetake Otsuka
-Configuration
1)Laser -> 2)QWP -> 3)HWP -> 4)Convex lens -> 5)BS -> 6)HWP
-Optical power measurement
output of 4) : 473mW
output of 4) ->Polarizer @ 90 deg : 1.8 mW
output of 4) ->Polarizer @ 0 deg : 391 mW
output of 5) : 272 mW
output of 6) : 219 mW
-Optical component specifications
Extinction Ratio of Polarizer : 0.46% (=1.8/391)
Transmittance of 5)BS @ polarized light : 69.6% (=272/301)
-Configuration of wave plate
2)QWP : 24 + 0.4
3)HWP : 144 + 0.5
-Confirm 6) is really HWP @ 1064 nm
-Beam profile
-Firstly, tried to measure the beam profile with 2 ND Filters:-
beam profile has terrible modal noise, so change one ND filter to gradient shutter.
-output of 6) : beam diameter 1.0 mm
-output of 6) -> Faraday Rotator : 0.7mm with some modal noise