Wideband magneto-optical characterization of HgCdTe

摘要

Abstract: Progress has recently been reported on the innovative technique of noncontact mapping of free carrier concentrations in mercury cadmium telluride by using the Faraday effect at discrete wavelengths. We describe here a modification of the basic setup to extend the range of materials covered. An interferometer output was used as a broad band source that covered the spectral region from 7 - 15 $mu@m. This permitted measurements of Faraday rotation to be made in HgCdTe material that could not be characterized with available single wavelength sources. Since Faraday rotation over the entire spectral region of interest was made, data could be extracted at optimum wavelengths for a given x value of the material. Data on HgCdTe is presented that show spectral regions where induced spin and where plasma contributions to the rotation predominate. The ability to do wide band Faraday rotation measurements opens up the possibility of extending the technique as a general analytical mapping tool for other classes of materials with potential applications in other fields. !7