Heterogeneous integrated phase modulator based on two-dimensional layered materials

Silicon nitride,with ultralow propagation loss and a wide transparency window,offers an exciting platform to explore integrated photonic devices for various emerging applications.It is appealing to combine the intrinsic optical properties of two-dimensional layered materials with high-quality optical waveguides and resonators to achieve functional devices in a single chip.Here we demonstrate a micro-ring resonator-based phase modulator integrated with few-layer MoS_(2).The ionic liquid is employed directly on the surface of MoS_(2) to form a capacitor configuration.The effective index of the composite MoS_(2)–SiN waveguide can be modulated via adjusting bias voltages to achieve different charged doping induced electro-refractive responses in MoS_(2) film.The maximum effective index modulation of the composite MoS_(2)–SiN waveguide can be achieved to 0.45×10^(−3).The phase tuning efficiency is measured to be 29.42 pm/V,corresponding to a V_(π)L of 0.69 V·cm.Since the micro-ring resonator is designed near the critical coupling regime,the coupling condition between the bus waveguide and micro-ring resonator can also be engineered from under-coupling to over-coupling regime during the charged doping process.That can be involved as a degree of freedom for the coupling tailoring.The ability to modulate the effective index with two-dimensional materials and the robust nature of the heterostructure integrated phase modulator could be useful for engineering reliable ultra-compact and low-power-consumption integrated photonic devices.