| Autor: |
A. P. Kotkov, N. D. Grishnova, N. I. Iakovleva, M. V. Sednev, K. O. Boltar, A. N. Moiseev, Vitaly I. Stafeev, E. V. Permikina, I. D. Bourlakov |
| Rok vydání: |
2005 |
| Předmět: |
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| Zdroj: |
SPIE Proceedings. |
| ISSN: |
0277-786X |
| Popis: |
The optical filter for 8-12 microns spectral range on the base of MCT epilayer grown by Metal Organic Chemical Vapor Deposition (MOCVD) has been investigated. The CdTe mole fraction in CdHg1Te equals x=O.24. The single-layer antireflection coatings for 10 tm peak wavelength have been deposed on the both sides of the filter. Transmission in 8-12 tmspectral range exceeds 70 %. Transmission at 7 im is of4O %, at 6 tm - 10 %, at 5 tm - less than 2 %. 1. INTRODUCTION The basic advantages of infrared (IR) focal plane arrays (FPAs) are associated mainly with their high quantum efficiency andsensitivity. The optical filter blocks the JR detector window transmission and decreases sensitivity outside the atmospheretransmission spectral bands used in the thermal infrared. The optical filter essentially improves remote objects identification dueto reduction ofnoise caused by the atmosphere turbulence.Located in cooled FPA zone optical filter also reduces background radiation. This additional advantage of cold optical filterincreases detectivity of each detector element for both staring and scanned focal planes and provides higher object temperatureworking range.Multiple spectral coatings are widely used for filters operating in 8-1 2 tm waveband. These filters performance is essentiallydepended on incident radiation angle. Therefore interference filters are ineffective for FPA-based JR systems with large apertureratio objective.The performance of optical filters on the base of ZnSe and PbSe materials has been investigated'.For 8-12 tm spectral range we use optical filters on the base of CdHgTe epitaxial layers, grown by MOCVD method frommetalorganic compounds and mercur?. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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