High optical power handling 1.2- to 2.2-micron-wavelength uncooled InGaAs photodiodes up to 6-GHz bandwidth for coherent spectroscopy

We report an uncooled, lattice-mismatched InGaAs photodiode for coherent spectroscopy that demonstrates linear performance up to a photocurrent of 70 mA and has a broad spectral coverage from 1.2 to 2.2 micron wavelength. The fiber-packaged photodiode module can deliver up to +13 dBm of continuous-wave RF output power, i.e. 2.8 V peak-to-peak amplitude, and does not require any further RF amplification to maximize the effective number of bits (ENOBs) for the backend digitizers. These photodiodes have a −3 dB bandwidth of 6 GHz and can coherently detect up to 6 spectral lines within a 1 ns temporal window.