Gemini Fallout On ISO.18 Yield

Gemini Fallout On ISO.18 Yield Why do the units that pass the 25dB spec fail at 30dB?Unit SNFailureG92LC2000479M2, low ports (2), 0dBG92LC2000443M1, M2 high ports (9), 0 and 2.5dBG92LC2000428ContaminationG92LC2000424contaminationG92LCN000302M2, low ports, 0dBG92LCN000303M2, low ports, 0dBUnit G92LC2000479

Failure near high edge of the frequency bandSlope value at 196250: 5.45

Unit G92LC2000479Most probable cause of this failure is : since the second orders are not optimally placed between ports, due to the unfortunately higher than normal slope for this particular unit, the grating was clipped at the high frequency and therefore some leakage from P2 into port P7 at higher frequencies. Slopes at lower frequencies were lower, so no leakage occurred.Unit G92LC2000443

PT 9 fails on both M1 and M2Unit G92LC2000443 contdHigh slope values on P9 M1 might explain the failure; however slope values on M2 are nominal.Yet isolation seems to be better on M1.Pixel periods used : M1 : 6.1 and M2: 6.

High slope near higher end of the spectrum on the lower ports, ~ 7.8-6.4.Unit G92LCN000302

Unit G92LCN000303

High slope near higher end of the spectrum on PT3 ~ 5.85.