Wavelength-Specific Optical Switch

Abstract

A wavelength-specific optical switch combines one or more tunable filters and bandblock reflectors such that the absorption or reflection of selected wavelength bands in the optical spectrum (visible, near infrared, or near ultraviolet) can be switched on and off. The wavelength switch is programmable, multifunctional, general-purpose, solid-state optical filter. The wavelength switch may serve as a tunable notch or bandblock filter, a tunable bandpass filter, a tunable highpass or lowpass filter, or a tunable band reflector. The wavelength switch has particular, but not exclusive, application in optics as a filter, band reflector, and as a means of isolating particular wavelengths or wavelength bands from a collimated light stream for transmission to, or rejection from, a sensor.

1 . A film for regulating reflection of incident radiant energy comprising
 a first optical material layer; and   a second optical material layer;   a temperature sensitive optical material positioned between the first optical layer and the second optical layer.   
     
     
         2 . The film of  claim 1 , wherein
 at a first temperature a first percentage of the incident radiant energy is reflected from the film and a second percentage of the incident radiant energy is transmitted through the film; and   at a second temperature a third percentage of the incident radiant energy is reflected from the film and a fourth percentage of the incident radiant energy is transmitted through the film.   
     
     
         3 . The film of claim  24 , wherein
 the first optical material layer reflects up to 50% of the incident radiant energy and transmits a majority of non-reflected radiant energy; and   the second optical material layer reflects up to 100% of radiant energy transmitted by the first optical material layer when the temperature sensitive optical material is above the threshold temperature and transmits up to 100% of radiant energy transmitted by the first optical material layer when the temperature sensitive optical material is below the threshold temperature.   
     
     
         4 . The reflective film of  claim 1 , wherein the film is in the form of a thin and flexible film. 
     
     
         5 . The film of  claim 1  further comprising a transparent substrate that supports the first optical material layer, the second optical material layer, and the temperature sensitive optical material. 
     
     
         6 . The film of  claim 5 , wherein the transparent substrate is a solid substrate. 
     
     
         7 . The film of  claim 1 , wherein a range of wavelengths of radiant energy regulated by the film comprises one or more of visual, infrared, or near-infrared wavelengths. 
     
     
         8 . The film of  claim 1 , wherein either or both of the first optical material layer and the second optical material layer is spectrally selective. 
     
     
         9 . The film of  claim 1 , wherein either or both of the first optical material layer and the second optical material layer comprises a combination of multiple optical material layers. 
     
     
         10 . The film of  claim 1 , where the temperature sensitive optical material is designed or selected based upon frequency dependent properties of the temperature sensitive optical material with respect to incident light to affect one or more of aesthetic, color, light or energy transmission, absorption, and reflection properties of the film.