BROADBAND FOCAL PLANE ARRAYS, OPERATING IN UV-TO-SWIR WAVELENGTH RANGE, ARE REQUIRED FOR ATMOSPHERIC MONITO…

Public award description

BROADBAND FOCAL PLANE ARRAYS, OPERATING IN UV-TO-SWIR WAVELENGTH RANGE, ARE REQUIRED FOR ATMOSPHERIC MONITORING OF GREENHOUSE GASES. CURRENTLY, SEPARATE IMAGE SENSORS ARE USED FOR DIFFERENT SPECTRAL SUB-BANDS: GAN FOR UV, SI FOR VISIBLE, AND INGAAS FOR SWIR, REQUIRING EXPENSIVE COMPONENT-LEVEL INTEGRATION FOR HYPER-SPECTRAL IMAGING. ALSO, THE SIZE OF THE INGAAS FOCAL PLANE ARRAYS IS CURRENTLY LIMITED BY THE INP SUBSTRATE AREA. WE PROPOSE A GAAS/INGAP/INGAAS BASED PHOTODIODE ON STANDARD GAAS SUBSTRATES FOR LARGE-FORMAT (4096 X 4096) FOCAL PLANE ARRAYS WITH THE FOLLOWING CHARACTERISTICS: (1) WAVELENGTH = 0.25 TO 2.5 MICRON; (2) QUANTUM EFICIENCY>30% IN UV (0.25 TO 0.4 MICRON),>80% IN VISIBLE (0.4 TO 0.9 MICRON), AND>70% IN IR (0.9 TO 2.5 MICRON) SUBBANDS; (3) PHOTODIODE AREA (SINGLE ELEMENT) = 15 X 15, 25 X 25, AND 50 X 50 MICRON SQUARE; (4) ROA>35 OHM-CM^2 AT 300K; AND (5) BANDWIDTH>1 GHZ. ADDITIONALLY, FEASIBILITY OF UV-TO-SWIR GRADED OPTICAL FILTERS WILL BE INVESTIGATED. BASED ON P.I.'S EXPERIENCE ON SCIAMACHY, THIS PROJECT WILL ENABLE ONE IMAGE SENSOR FOR 8 SPECTROSCOPIC CHANNELS CURRENTLY ORBITING ON EUROPEAN SPACE AGENCY'S ENVISAT. ALSO, FEASIBILITY OF LARGE-FORMAT IMAGE SENSORS ON GAAS SUBSTRATES WILL BE DEMONSTRATED.