Integrated RF Passive Low-Pass Filters in Silicon Photonics

The integration of passive radio frequency (RF) components, such as resistors, capacitors, and inductors, requires a relatively large area on complementary metal-oxide-semiconductor chips, which is not cost-effective in developing optical receiver front-ends. This could be addressed by implementing passive RF components on silicon photonics chips. In this letter, we present an on-chip passive RF low-pass filter coupled to an integrated photodetector. This letter demonstrates that passive RF analog processing can be implemented in a commercial silicon photonics platform. The performance of the implemented RC filters is reported at frequencies up to 15 GHz.