Polarization-insensitive, silicon-photonics circuit, four-mode spatial multiplexer matched to a rectangular core fiber

We design and test a SiPh mode multiplexer circuit, utilizing 3µm-thick ridge waveguides having low polarization dependence. The multiplexer achieves low loss (2-3dB) and low PDL (<0.8dB) across the C-band. Output modes are coupled to rectangular core fiber.