array of red LEDs at 660 nm

1
Original MSE In-Vessel Calibtion Jig (9/22/03)
film polarizer in frame (0o, 90o, 10o)
circular polarized
array of red LEDs at 660 nm
filter holders (commercial)
existing mounting flange (connection to bench
TBD)
adjustable leg
MSE turret
Remotely controllable Rotating filter
mount. Linear/circular polarizers
2
MSE In-Vessel Calibration Jig (9/22/03)
LED array
Diffuser
Polarizer
q1
q2
q3
MSE optics
3
Orientation of Polarized Light Differs from
Polarizer Transmission Axis Unless Polarizer
Surface is Normal to Viewing Direction

• b qobserved-q
• 0 ltanygt 0.00
• 90 ltanygt 0.00
• 0 0.00
• 10 10 0.15
• 10 20 0.63

- Same is true for rotation about horizontal axis
4
New Calibration Apparatus Keep
Polarizer Perpendicular to each MSE sightline
LED array
Diffuser
Polarizer (on rotating stage)
MSE optics
5

• Illuminate polarizer with backlight through
  fibers then adjust orientation of polarizer
  until the reflected light hits lens L1 this
  ensures that polarizer is perpendicular to
  sightline.
• Stability of apparatus is important over a 30
  cm arm, a vibration of 50 microns change in
  angle of 0.1 degrees.
• Studies with circularly polarized light will be
  interesting.