Patent ID: 6185040
Filing Date: 2001-02-06
Classification: G02B

Abstract:
An apparatus receiving an input light at a respective wavelength within a continuous range of wavelengths, the apparatus comprising:an angular dispersive device having first and second surfaces, the second surface having a reflectivity which causes a portion of light incident thereon to be transmitted therethrough, the first and second surfaces being positioned so that the input light is reflected a plurality of times between the first and second surfaces to cause a plurality of lights to be transmitted through the second surface, the plurality of transmitted lights interfering with each other to produce an output light which is spatially distinguishable from an output light produced for an input light at any other wavelength within the continuous range of wavelengths; anda spacer element maintaining the relative positioning between the first and second surfaces to be constant, the spacer element having a thermal expansion coefficient with a magnitude which is less than or equal to 10.sup.-5 /.degree. C.