Mode multiplexing 1x4 waveguide optical switch based on phase-change materials

With the explosive data growth over internets and communications, traditional optoelectronic switching technologies meet many challenges, such as the lower switching speed, insufficient capacity and excessive power consumption et al. The optical interconnect technologies have developed and present very good advantages, e.g. the expanded bandwidth, high switching speed, low energy consumption, small sizes and high integration. Optical switch is a kind of very critical components for optical interconnect technologies. In this paper, we propose a mode multiplexing 1x4 waveguide optical switch structure, which is a silicon based integrated switch with non-volatile chalcogenide optical phase-change material (C-OPCM) thin films. The optical mode transmission characteristics of the switching paths analyzed and calculated by the supermode coupling theory. The optical switch device is theoretically modeled and analyzed by using a three-dimensional finite-difference time-domain (3D-FDTD) method. The 1x4 optical switch device can transmit different optical modes by switching different phase states of C-OPCM films. As inputting a TE0 mode, the outputs are four different order modes of TE0, TE1, TE2, and TE3. Different switching channels select different transmission modes. Such a 1x4 optical waveguide switch presents low insertion losses (ILs) and relative high extinction ratios (ERs). The insertion losses are respectively as low as 0.7 dB, 0.27 dB, 0.15 dB, and 0.54 dB for TE0 mode at output portO1, TE1 mode at output port O2, TE2 mode at output port O3, and TE3 mode at port output O4. The extinction ratios are separately as high as 20.3 dB, 23.29 dB, 17.55 dB, and 18.63 dB. This kind of phase-change optical switch devices exhibit excellent transmission characteristics, non-volatility, and smart structures and high integration, which have potential application values in the fields of photonic integration and photonic networks.