Optically Pumped Mixing in Photonically Integrated Uni- Travelling Carrier Photodiode

We report the first demonstration of optically pumped mixing using a monolithically integrated photonic chip. On that chip, uni-traveling carrier photodiodes (UTC-PDs) were monolithically integrated with two lasers to generate the optical heterodyne that will drive the optically pumped mixing. The two DFB lasers wavelength spacing was tuneable from 70.5 GHz to 92.4 GHz. When an RF signal at 70 GHz was supplied to the UTC-PD with the optimum voltage bias, the UTC-PD successfully downconverted the RF signal to an intermediate frequency (IF) that was tuneable from 0.5 GHz to 16.4 GHz. These results demonstrate the potential of this photonic integrated circuit in spectroscopy, sensing and as millimeter wave wireless receivers.