Indium Arsenide: A Simpler Solution!

Key characteristics:

• Transmission edge is 3.1µm at 80K (cryogenic)
• Transmission edge is 3.8µm at 298K (room temperature)
• Refractive index comparable to silicon in 3-5µm, 8-12µm spectral bands
• Complete blocking below 3.0µm due to natural material absorption

InAs combines the refractive index profile of silicon with a short-wavelength blocking range broader than germanium.  Reynard Corporation routinely manufactures InAs windows with surface qualities approaching 10-5 per MIL-PRF-13830.  Substrates can be coated and verified to meet any customer spectral requirement from room temperature to 80K.  Coatings are routinely verified to pass the adhesion, humidity, and moderate abrasion requirements of MIL-C-48497A

Benefits:

InAs enables infrared optical system designers to explore the trade space between improved system performance and allowable manufacturing tolerances. The extended blocking range offered by InAs also enables manufacture of high performance, fully-blocked filters in the 3-5µm and 8-12µm spectral bands. In comparison to classical approaches, InAs based thin-film coatings require fewer layers to meet out-of-band blocking specifications while maintaining superior in-band transmission.

"Using InAs instead of the more commonly known IR materials can reduce optical component production costs which results in lower system costs with improved optical performance" says Forrest Reynard, President of Reynard Corporation.

Eliminating “dig” defects is of paramount importance for filters used above focal plane arrays (FPA’s) as such defects render blind any underlying pixels. Samples manufactured by Reynard Corporation have been verified to approach 10-5 per MIL-PRF-13830.

Applications:

• Cryogenic filters for remote sensing
• IR imaging, single band and multi band

Click here to request a quote for custom thin film coatings.

Reynard Corporation operates per Military Specification MIL-I-45208.