2023·Optics Express · 31(16)·First author·IF 3.8

Inverse design of an ultra-compact dual-band wavelength demultiplexing power splitter with detailed analysis of hyperparameters

A. Sun, et al.
Fudan University

TL;DR A series of ultra-compact dual-band wavelength-demultiplexing power splitters (WDPS) that perform wavelength demultiplexing and 1:1 power splitting simultaneously — for dual-band passive optical networks. Designed on standard SOI with a novel two-step direct binary search (TS-DBS), with the impact of optimization hyperparameters analysed in detail. A 130 nm-feature WDPS shrinks footprint 12.77× vs forward design; a 65 nm-feature WDPS reaches 0.36 / 0.37 dB insertion loss and −19.91 / −17.02 dB crosstalk at 1310 / 1550 nm.

Dual-band wavelength demultiplexing splitter

Background

Inverse design is a widely studied route to shrink footprint and boost performance of integrated silicon-photonic devices. Dual-band PONs need a single device that performs both wavelength demultiplexing and 1:1 power splitting — hard to achieve compactly with conventional forward design.

Method & Results

Using a novel two-step direct binary search (TS-DBS) on standard SOI, we design a family of dual-band WDPS and analyse how hyperparameters shape performance: a 130 nm-feature device achieves 12.77× footprint reduction, and a 65 nm-feature device reaches 0.36 / 0.37 dB loss and −19.91 / −17.02 dB crosstalk at 1310 / 1550 nm.

Highlights

Simultaneous dual-band wavelength demultiplexing + 1:1 power splitting for dual-band PONs
Two-step direct binary search (TS-DBS); 12.77× footprint reduction vs forward design
0.36 / 0.37 dB loss and −19.91 / −17.02 dB crosstalk at 1310 / 1550 nm (65 nm feature)
First systematic study of optimization hyperparameters in inverse design

Citation

A. Sun et al., "Inverse design of an ultra-compact dual-band wavelength demultiplexing power splitter with detailed analysis of hyperparameters," Optics Express, 31(16), 2023.