Designing an Optical Router Based on a Multimode-Interference Silicon-On-Insulator Coupler with Tunable Power Transmittance

The demand on fast and high-bandwidth data transmission is in continuous increase. These demands are highly dependent on optical signal manipulation, including switching, modulation, and routing. We demonstrate a two-port silicon optical router based on the multimode interferometer (MMI) configuration. The same MMI structure was used for both inward and backward waveguiding to reduce the total length of the device. A phase shifter consisting of two ring-like waveguides made of silicon p-n junctions was used to introduce the phase shift needed for optical routing upon voltage application. Two designs for the MMI optical router were studied: Firstly, a conventional MMI with a crosstalk ratio of 15.1 dB was investigated. Finally, an angled MMI reaching a crosstalk ratio of 18.2 dB at a wavelength of 1.55 μm was investigated.