High-speed mid-wave infrared holey photodetectors

Abstract

We demonstrate high-speed mid-wave infrared photoconductive detectors leveraging a lattice-mismatched, epitaxially grown InSb absorber material patterned with nanometer-scale hole arrays. We show that the nano-scale hole patterns allow for post-growth control over the detector response time by introducing recombination surfaces to increase non-radiative recombination. The photoconductive pixels are integrated into a microwave coplanar waveguide for high frequency characterization. The detector response is characterized as a function of temperature and hole-array dimensions. We show a detector response with characteristic time scales of tens of picoseconds and bandwidths up to 7 GHz at room temperature. The presented detectors offer a mechanism for engineering response times in long wavelength detectors for potential applications in high-speed sensing/imaging, free-space communication, ranging, or dual-comb spectroscopy.