GHz, Octavespanning Photodetectors for MWIR/LWIR

Exploitation of new chip-scale optical frequency comb sources demands improvements in MWIR/LWIR detector performance, including: High speed (5 GHz); high sensitivity (NEP < 1pW/Hz1/2); broad spectral response (Octave); and thermo-electric cooler (TEC) operating temperature. No existing detector meets these demanding performance parameters. Phase I successfully designed and demonstrated an octave spanning (3-6 µm) III-V based MWIR detector using a barrier diode architecture with excellent NEP meeting spec at 200K. Phase II will optimize the MWIR (3-6 ?m) detector design and fabrication process, and will design, manufacture and test a LWIR detector combining the properties of SWIR pin and MWIR/LWIR photodetectors in a way that harvests the advantages of each so that all performance requirements are met. Specifically, we will construct detectors with a built-in field in the absorber layer to rapidly sweep out carriers and a patented barrier layer architecture to suppress dark current. Phase II will further develop both MWIR (3-6 µm) and LWIR (6-15 µm) prototype detector systems with integrated thermo-electric cooler (TEC), focusing lens and high-bandwidth, low-noise transimpedance amplifier. Amethyst is also working with key members of the DARPA SCOUT program to ensure integration of these detectors into dual-comb spectrometers for advanced chemical/gas sensing capabilities.