Assessment of PbSe Photoconductors for the Realization of Free-Space Midinfrared Optical Communication Links

PbSe-photoconductor technology has been revisited to ascertain its feasibility for the realization of free-space midinfrared optical links operating at room temperature. Results show that receivers based on current PbSe devices can perform up to 3 Mb/s with a bit-error-rate-limited sensitivity at 10
^-9
better than 50 μW. Calculations indicate that the temporal response depends on the density of sensitizing centers, leading to an improvement in the gain-bandwidth product for high mobility material if designed properly.