Investigation of ultra wideband multi-channel dichroic beamsplitters from 0.3 to 52µm

Zhang, K. Q., Hunneman, R., Seeley, J. S. and Hawkins, G. J. (1990) Investigation of ultra wideband multi-channel dichroic beamsplitters from 0.3 to 52µm. Infrared Physics & Technology, 30 (1). pp. 45-53. ISSN 1350-4495 doi: 10.1016/0020-0891(90)90040-3

Abstract/Summary

The development of a set of multi-channel dichroics which includes a 6 channel dichroic operating over the wavelength region from 0.3 to 52µm is described. In order to achieve the optimum performance, the optical constants of PbTe, Ge and CdTe coatings in the strongly absorptive region have been determined by use of a new iterative method using normal incidence reflectance measurement of the multilayer together with initial values of energy gap Eg and infinite refractive index n for the semiconductor model. The design and manufacture of the dichroics is discussed and the final results are presented.