Optical Waveguiding and Electrooptic Modulation in Ion Implanted CdTe

Abstract

Optical waveguides and waveguide-type electrooptic modulators at 1.15 µm are fabricated by H+ ion implantation at 1 MeV into CdTe. The RHEED pattern shows that the ion implanted CdTe does not suffer serious damage compared to the case in GaAs. The absorption loss of the TE0 mode of 2.4cm-1 is obtained at 1.15 µm in as-implanted sample, in which 3×l014/cm2H+ ion is implanted. This value is quite less than that in as-implanted GaAs optical waveguides. By the ion implantation, crystal defects are introduced in CdTe crystal to make compensation centers of free carriers, but the crystal still has its macroscopic ordering to keep the low absorption loss and the value of electrooptic coefficient in the bulk. By using the Schottky-type electrode, as-implanted CdTe with a dose of 1015/cm2 at 1 MeV is shown to act as an electrooptic modulator at 1.15 µm. The transmission ratio of 23.4% at applied voltage of 54 V is obtained.