A single 1" borosilicate glass collimating lens at the exit port is standard on the Model 201-100 and TH3 lamp housings. This lens not only improves light collection efficiency to f/1.5, but also filters harmful UV rays while allowing visible and IR light to pass through (360-2350nm). This option upgrades the borosilicate glass to ZnZe such that wavelengths 0.55-10.6μm can pass through as well. Zinc Selenide has a high transmission from 550nm to 16μm.

Technical Specifications
Material: ZnSe (Laser Grade)
Design wavelength: 10.6µm
Clear Aperture: 80% Diameter
Diameter Tolerance: +0.00mm/-0.13mm
Center Thickness Tolerance: ±0.25mm
Surface Accuracy: 1 λ @ 10.6µm
Surface Quality: 40–20
Coating: None