Measurement of the d(36) coefficient of mercury cadmium telluride by reflection second harmonic generation

The second order nonlinear coefficient (d(36)) of the narrow band gap semic onductor, mercury cadmium telluride (MCT), is measured. Because MCT is stro ngly absorbing at a 1.06 mum wavelength, the measurement was performed by c omparing the second harmonic intensity reflected from the material surface to the second harmonic intensity measured for a quartz sample in transmissi on. The analysis depends on the derivation of comparable expressions for th e reflected and transmitted intensities. Using this approach a value of d(3 6) = 350 +/- 40 pm/V is obtained, a value much larger than those reported f or similar zinc-blende type materials. The large magnitude of the MCT d(36) is attributed to an electronic resonance enhancement. (C) 2001 American In stitute of Physics.