G. Gaini, M. Azoulay, C. Shiloh, Y. Noter, A. Saya, H Galron, M. Roth
Optical Engineering, Vol. 28, Issue 9, 281003, (September 1989) https://doi.org/10.1117/12.7977078
TOPICS: Crystal optics, Crystals, Germanium, Modulation transfer functions, Infrared radiation, Thermography, Refractive index
Large single crystals, up to 200 mm in diameter, of high optical quality germanium have been grown by the Czochralski technique. Post-growth thermal treatment improves the optical homogeneity and reduces optical losses, as shown by measurements of refractive index gradients and modulation transfer function (MTF). A new approach for the piecewise combination of interferograms, as well as a polychromatic treatment of MTF, is presented.