Programmable waveguide mesh photonic integrated circuits based on thin-film lithium niobate

Programmable photonics chips based on a versatile structure are crucial for the next generation of advanced photonics systems. In this paper, we designed a programmable photonics chip with a hexagonal waveguide mesh consisting of longitudinally parallel arranged tunable basic units based on thin-film lithium niobate. We fabricated a waveguide mesh on a chip with an effective area of 5.2<i>m</i> <i>m</i>×1.5<i>m</i> <i>m</i>, which contains six tunable basic units, and tested its performance. The extinction ratio of both output ports of the tunable basic units exceeded 15 dB, with <i>P</i> _π=46<i>m</i> <i>W</i> and a response time of about 32 µs. By programming the waveguide mesh through a PC, it can be configured as a multi-channel adjustable optical switch, where the extinction ratio of each output port is greater than 15 dB. This can be applied to all-optical networks for arbitrary path switching.