How to choose infrared optical glass lenses

When selecting infrared optical glass lenses, the following key factors need to be considered:

Wavelength Range: Different infrared optical glass lenses are suitable for different wavelength ranges. For example, germanium (Ge) is suitable for the mid infrared band of 2-14 microns, silicon (Si) is suitable for the mid infrared band of 1-7 microns, zinc selenide (ZnSe) is suitable for the mid infrared and long wave infrared bands of 0.6-18 microns, and zinc sulfide (ZnS) is suitable for the mid infrared and long wave infrared bands of 0.4-12 microns. Choosing the appropriate wavelength range can improve the performance of the lens in specific applications.

Transmittance and reflectivity: The transmittance and reflectivity of infrared optical glass lenses directly affect their optical performance. High transmittance and low reflectivity lenses can increase the overall transmittance efficiency of the system. For example, anti reflective coatings can reduce the reflection on the surface of the lens and increase the transmittance of light.

Mechanical performance and environmental adaptability: The mechanical performance and environmental adaptability of lenses are also factors that need to be considered when choosing. For example, germanium has high density and hardness, and can work stably over a wide temperature range, but it is heavy and costly; Zinc sulfide has good mechanical properties and environmental adaptability, and is suitable for various optical systems.

Cost and availability: The cost and availability of different materials can also affect the choice. For example, although germanium and zinc selenide have good performance, they are expensive; Silicon and zinc sulfide have relatively low prices and are easy to obtain.

Suggestions for selection in specific application scenarios:

Infrared imaging system: Germanium or zinc sulfide lenses can be chosen because they have high transmittance and good mechanical properties in the mid infrared band.
High power laser system: Zinc selenide is a good choice because it has high transmittance and low absorption in the long wave infrared band.

Spectrometer and laser system: Magnesium fluoride (MgF2) and calcium fluoride (CaF2) are suitable for short to mid infrared wavelengths and have good chemical resistance and mechanical stability.