Wavelength stabilizing laser mirror

Abstract

A high performance wavelength stabilizing laser mirror/output coupler, particularly useful for stabilizing a laser cavity within a narrow bandwidth, is described, which comprises a substrate of selected material on which is deposited an optical coating having a refractive index profile over the thickness thereof which is selectively continuously modulated between preselected high and low values to define a preselected narrow reflectance spectrum.

I claim: 
     
       1. A high performance wavelength stabilizing laser mirror/output coupler device for stabilizing a laser cavity within a narrow bandwidth, which comprises: (a) a substrate of selected optical material;   (b) a coating of optical material deposited to a preselected thickness on said substrate; and   (c) wherein said coating has a refractive index profile over said thickness thereof which is selectively continuously modulated between preselected high and low values to define a preselected narrow reflectance spectrum for said coating.   
     
     
       2. The device of claim 1 wherein said substrate comprises an optical material selected from the group consisting of fused silica, silicon and zinc selenide. 
     
     
       3. The device of claim 1 wherein said optical coating comprises an optical material selected from the group consisting of silicon dioxide, titanium dioxide, magnesium fluoride, thorium fluoride, zinc selenide and zinc sulfide. 
     
     
       4. The device of claim 1 wherein said refractive index profile of said optical coating is in the form of a sine wave, and said coating has an optical thickness of about 20 to 50 microns or about 50 to 250 cycles of said sine wave.