Spectral range of 1.5-5 µ m, average transmittance of 90%, average contrast>2; 000:1 Incident angle 0 ± 20 ° Optical coating High efficiency anti reflection coating Transmission direction ± 2 ° Available outer diameter 25.4 mm; 38.1 mm; 50.8mm optical aperture 15.4 mm; 25.4 mm; 38.1 mm maximum temperature 200 ° C substrate material silicon