Thermo-Optical Switches With Silicon-on-Insulator Waveguide Reflective Guided-Mode Goos-H?nchen Effect

The development and applications of modern fiber-optic communications and computer data communications have led to the increasing demands for silicon-based photonic integrated devices,especially for the optical devices based on silicon waveguide planar lightwave circuit(PLC)technology.At present,wavelength division multiplexing,optical splitter,and optical coupling devices have been widely used in industry,so the need for another more critical core device: optical switches,optical switch arrays and matrix optical switches is also more urgent.In this work,on the waveguide platform of silicon-on-insulator(SOI),an efficient Goos-H?nchen(GH)spatial shift of the reflective guided-mode is implemented with a waveguide corner mirror(WCM)structure and further with an effective combination of the GH spatial shift and the thermo-optic(TO)refractive index modulation(RIM),the function of a digital TO switch is realized.In research on such a digital optical switch.Then,the systematic simulations are carried out with the theoretical model built for defining the GH spatial shift and the professional simulator of optical field – the finite difference time-domain(FDTD).At a given incident angle,the spatial GH shift can be optimized so that a great jump of reflected beam displacement is reached under a TO-RIM effect.As a result,with an eigenstate matching of the reflected guided modes between a single-mode input waveguide and a multimode interference(MMI)structure,the functions of a 1x3 or 1x2 digital optical switch are experimentally demonstrated and the consistent switching processes at two adjacent output ports under an alternating drive signal of electric voltage are observed.In experiments,a device structure caused optical loss of 0.3 dB,a switching power of 130-150 mW,a switching time of about 50?s and an output isolation of 15 dB are measured.In addition,by comparing with the recent results of Mach-Zehnder interferometer(MZI)based 2x2 TO switch,the advancements of a GH shift based digital TO switch in this work are presented,and its potential applications in future is evaluated and predicted.