Ultra-Compact Power Splitters with Low Loss in Arbitrary Direction Based on Inverse Design Method

The power splitter is a device that splits the energy from an input signal into multiple outputs with equal or uneven energy. Recently, the use of algorithms to intelligently design silicon-based photonic devices has attracted widespread attention. Thus, many optimization algorithms, which are called inverse design algorithms, have been proposed. In this paper, we use the Direct Binary Search (DBS) algorithm designed with three 1 x 3 power splitters with arbitrary directions theoretically. They have any direction and can be connected to other devices in any direction, which greatly reduces the space occupied by the optical integrated circuit. Through the simulation that comes about, we are able to get the insertion loss (IL) of the device we designed to be less than 5.55 dB, 5.49 dB, and 5.32 dB, separately. Then, the wavelength is 1530-1560 nm, so it can be used in the optical communication system. To discuss the impact of the footprint on device performance, we also designed another device with the same function as the second one from the above three devices. Its IL is less than 5.40 dB. Although it occupies a larger area, it has an advantage in IL. Through the design results, three 1 x 3 power splitters can be freely combined to realize any direction, multi-channel, ultra-compact power splitters, and can be better connected with different devices to achieve different functions. At the same time, we also show an example of a combination. The IL of each port of the combined 1 x 6 power splitter is less than 8.82 dB.