InAs avalanche photodiodes have demonstrated the best ionisation properties of III-V
semiconductors, operating as an electron-only multiplier. This permits negligible excess noise and constant bandwidth even at high gain. InAs offers the potential of high bit-rate optical detection at wavelengths of up to 3μm, opening up large parts of the spectrum for low photon and single-photon detection, ideally for gas sensing and defence and security applications. By combining superlattice absorption region, we will expand our programme into MWIR. Working with the rest of the project on ROICs, microlenses and lidar applications, we plan to utilise and enhance performance of this exciting material system. WP2 is led by Chee Hing Tan and will feed into WPs 3, 4, 5 and 6.