High-pressure Bridgman grown CdZnTe for electro-optics applications

The linear electro-optic response of high pressure Bridgman growth semi-insulating Cd0.9Zn0.1Te bulk samples has been characterized. Measurements have been performed in the third optical window for telecommunications around λ = 1.5 μm. The dependence of the Pockels figure of merit on the modulation frequency and on the intensity of the optical probe beam is presented and discussed. Despite the residual optical absorption, Cd0.9Zn0.1Te is not affected by photo-generated auto-inhibition of the Pockels effect. This can be attributed to the action of an efficient intragap recombination center. It is, therefore, a suitable basic material for electro-optic switching of near-infrared beams at low frequency and quasi-continuous wave (cw) regimes. The implementation of a Cd0.9Zn0.1Te-based cross-bar switch for optical communication applications is also presented, which reaches -30 dB of extinction ratio and sub millisecond response time.