Mode insensitive switch for on‐chip interconnectmode division multiplexing systems

A mode insensitive switch is proposed and experimentally demonstrated on a silicon-on-insulator platform using a balanced Mach–Zehnder interferometer structure with a mode insensitive phase shifter for on-chip mode division multiplexing interconnects. Switching the first three quasi-transverse electric (TE) modes, consuming less than 40 mW power is demonstrated. The whole system exhibits approximately $ - {2},\;{ - 3.7}$−2,−3.7, and $ - {5.2}\;{\rm dB}$−5.2dB insertion loss for the TE0, TE1, and TE2 modes at 1550 nm, respectively. The corresponding crosstalk is less than $ - {8.6}\;({\rm - 9}), {- 8} ({ - 10.3})$−8.6(−9),−8(−10.3), and $ - {10}\;{\rm dB}$−10dB ($ - {10.3}\;{\rm dB}$−10.3dB) within the wavelength range of 40 nm (1535–1575 nm) for the cross (bar) states, respectively. The extinction ratios (ERs) for the cross (bar) states are 20.1 (19.5), 22.8 (33.7), and 15.4 dB (18.1 dB) for the TE0, TE1, and TE2 modes at 1550 nm, respectively. The payload transmission is also conducted using non-return-to-zero pseudorandom binary sequence (PRBS)-31 data signals at 10 Gb/s for single-mode transmission and simultaneous three-mode transmissions. For all the scenarios, open eyes are observed.