Planar lightwave circuit balanced optical fanout using a thin photodetector array embedded in a polymer MMI coupler

In this paper, a balanced optical fanout using 1×4 thin film metal-semiconductor-metal (MSM) photodetector array embedded in a photoimageable polymer multi-mode interference (MMI) coupler is fabricated, demonstrated, and compared to theoretical estimates. This is the first MMI coupler reported with an integrated photodetector array, and the first MMI coupler reported that has been fabricated with a photoimageable polymer. For optical signal distribution (e.g. optical clock distribution), balanced signal routing is an important optical function, and MMI couplers provide compact design, low splitting loss, and balanced output.