Design, fabrication and metrology of 10$\,\times\,$100 multi-planar integrated photonic routing manifolds for neural networks

TL;DR

This paper presents the design, fabrication, and characterization of multi-planar silicon nitride photonic routing manifolds with 10 inputs and 100 outputs, demonstrating precise light distribution for neural network applications.

Contribution

It introduces a novel multi-planar integrated photonic architecture with rapid measurement techniques and high-precision power distribution capabilities.

Findings

Achieved mean power output errors of 0.7 and 0.9 dB for uniform and Gaussian distributions.

Demonstrated effective use of top-view imaging for rapid transmission measurements.

Validated high-performance passive photonic components within the system.

Abstract

We design, fabricate and characterize integrated photonic routing manifolds with 10 inputs and 100 outputs using two vertically integrated planes of silicon nitride waveguides. We analyze manifolds via top-view camera imaging. This measurement technique allows the rapid acquisition of hundreds of precise transmission measurements. We demonstrate manifolds with uniform and Gaussian power distribution patterns with mean power output errors (averaged over 10 sets of 10 inputs) of 0.7 and 0.9 dB, respectively, establishing this as a viable architecture for precision light distribution on-chip. We also assess the performance of the passive photonic elements comprising the system via self-referenced test structures, including high-dynamic-range beam taps, waveguide cutback structures, and waveguide crossing arrays.