| Popis: |
Supersmooth mirror substrates for laser-gyro applications were investigated. Bare samples made of BK7 glass, fused silica, and different silicon wafers were examined. Nomarski differential interference contrast microscopy was used to characterize the quality of the surfaces using a specially selected microscope objective with ultralow internal light scatter. The microscope system resolved a root mean square roughness in the range of 0.05 nm. Photographs of these supersmooth surface structures are presented. To obtain additional information, the total integrated light scattering of the bare substrates was measured. An Ulbricht integrating sphere with a diameter of 0.125 m was used for this purpose. Unwanted light scatter by the rear side of the transparent substrate was blocked using a special diaphragm. A specially developed polishing process that yields surfaces with a roughness of about 0.1 nm and probably lower is discussed. |
