IR lenses are types of lenses that are used by specific abstracts. They are used to collect, focus and collimate rays of light in short wave, mid-wave or the long wave infrared spectra. They use the substances in coatings to perfect the performance of objects operating above 700nm containing thermal imaging or spectroscopy. The infrared rays have a range of 700-1600nm wavelengths. When they are into small units; NIR refers to 700-900nm, SWIR ranges in 900-2300nm MWIR has 3000-5000nm, while LWIR contains 8000-12000nm wavelengths.
Most companies like Edmund Optics provides several types of IR lenses including the singlet lenses, achromatic lenses, aspheric lenses, and some focusing objectives that perform well in the part of the infrared spectrum. The IR glasses are necessary for use in many industrial or any defense applications like FTIR spectroscopy.
Examples of IR lenses
They appear in different shapes and sizes, although they perform the same function. They include, germanium meniscus lenses, calcium fluoride double convex lenses, calcium fluoride Plano-convex lenses, germanium infrared aspheric lenses, etc. The optical coatings should be highly durable, diamond-like coatings and have broadband anti-reflective material that perfects their functions.
Importance of using good material on the IR lenses
The international relation lenses provide a conceptual framework to view the target objects. Infrared light has longer wavelengths than the visible light. The two regions do not work together when passing through the same medium. The fused silica, BK7, and Sapphire are the best material for using in the IR lenses. Materials are picked depending on the task at hand. To understand the concepts of getting the best content consider transmission, index of refraction, dispersion and gradient index of the cameras.
The purpose of the IR filters in cameras
The IR filter is a colored filter that blocks the passing of the infrared light. The color spectrum, noticed by the human eye is limited while the spectrum, seen by the CCD camera is not restricted. The IR lenses help in showing the real colors of the objects.