07 Jun 2022 To learn more about TIR lenses, click here.
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A TIR lens is an optical lens built on the principal of total internal reflection (TIR). TIR lenses collimate light, sending out a concentrated beam of full intensity. They are used in a wide variety of applications, including collimating the beams from high power LEDs. Shanghai Optics produces high quality TIR lenses suitable for a wide variety of different purposes.
Understanding TIR Lens Design
Typically TIR lenses are cone shaped compound lenses with rotational symmetry. Composed of a refractive lens inside of a reflector, they can produce smooth circular beams with minimal FWHM widths. The refractive lens receives the light, then transmits it to the reflector which processes and shapes the beam. The mechanism behind this has to do with Snell’s law and some important optical principals.
Light is refracted, or turned from its original path, at any place where it reaches an interface between two materials with different refractive indices. If the first material has a higher index of refraction than the second, Snell’s law tells us that the angle of refraction will be more than ninety degrees. Where the angle of incidence is greater than a critical angle, the light will be reflected into the material. We call this total internal reflection. The beam angle depends on the curvature of the TIR surface for your specific lens. | 
