Experimental study of an In0.53Ga0.47As–InP resonant plasma waveguide modulator for medium-infrared light

We report on the first experimental study of a medium-infrared waveguide modulator based on the coupling between a dielectric grating coupler and an In0.53Ga0.47As–InP waveguide, operating near cut off, and containing a resonant semiconductor plasma. The prototype designed for demonstrating this novel effect was grown by metalorganic chemical vapor deposition. The experimental results show low power (225 mW), low voltage (15 V) operation for obtaining a modulation depth of 30%. The overall transmission efficiency is, however, rather low (0.5%) due to the wet chemical etching techniques used for defining the grating structure.