Wire grid polarizer test : (2) results with titling effects included

1. Wire grid polarizer test : (2) results with titling effects included :(3) results with a protective glass (‘blank’) Jinseok Ko and Steve Scott DNB Meeting June 20, 2005

2. last time … “uwg” test setup “ugw” test setup glass side wire side wire side glass side (unpolarized) collimated LED (unpolarized) collimated LED detector rotational polarizer detector rotational polarizer wire grid polarizer wire grid polarizer with various reference transmission axes (“rta”) 90 180 0 For various reference transmission axis between 0 to 180 (0, 1, 5, 10, … , 89, 90, 91, … 170, 180)

3. now, we want to simulate the same configuration as in the vessel  5 MSE object lens light source (DNB line) wire grid polarizer with two possible directions protective glass (‘blank’)

4. new test setups “uwg” setup “ugw” setup glass side wire side wire side glass side (unpolarized) collimated LED (unpolarized) collimated LED detector rotational polarizer detector rotational polarizer wire grid polarizer wire grid polarizer “ubwg” setup “ubgw” setup protective glass (“blank”) protective glass (“blank”) (unpolarized) collimated LED (unpolarized) collimated LED detector rotational polarizer detector rotational polarizer wire grid polarizer wire grid polarizer vertical tilting effect +1.5, 3.5, 5.0 -1.5, 3.5, 5.0

7. uwg & ugw (reference cases) : shows w/g position difference

8. ugw & ugw051p & ubgw051p : shows blank and tilting effects

9. uwg & ubwg051p : also shows blank and tilting effects

10. explicit tilting effect is observed in the linear behavior

11. However, inclusion of tilting and blank effect does not explain the observation in the vessel Invessel observation  3 degrees variation

12. observations • The protective glass (“blank”) between the light source and the wire-grid polarizer • does not affect the measured polarization angle much in either cases (wg or gw). • . • Tilting affects the linear behavior that exists in the measured polarization angle • variation along the angles of incidents. • “Inverse-matching” phenomenon (that is, “uwg” data more match “acgw” (or “agw”) • predictions and “ugw” more to “aw” predictions) still not resolved. • Even including tilting and blank effects does not explain the observation from the • from the invessel polarizer test. next … • Same tests with a dichroic (plastic) polarization sheet • Develop analytic predictions that include the tilting effects, the additional polarization • changes due to glass substrate and/or AR coating layer

13. analytic predictions were as following and only involves possible changes in angles of incidents wire grid air “aw” air coating air glass “acw” “agw” air coating glass air glass coating “acgw” “agcw”

14. these predictions match with the data for parabolic coefficients but not for linear coefficients u b w g 5.1p configuration u b g w 5.1p configuration

15. z new prediction that includes the tilting effects  z`  y` (mse_memo_49b) y  x

16. u b g w 5.1p configuration with new prediction

17. observations • The protective glass (“blank”) between the light source and the wire-grid polarizer • does not affect the measured polarization angle much in either cases (wg or gw). • . • Tilting affects the linear behavior that exists in the measured polarization angle • variation along the angles of incidents. • New prediction with tilting effects, although not for all reference transmission axes, • implies this. • “Inverse-matching” phenomenon (that is, “uwg” data more match “acgw” (or “agw”) • predictions and “ugw” more to “aw” predictions) still not resolved. • (Most seriously,) none of the measured data (or configuration) resembles the • profile from the invessel polarizer test done with the LED light source. next … • Same tests with a dichroic (plastic) polarization sheet • Develop more rigorous predictions that include the additional polarization changes • due to glass substrate and/or AR coating layer