Large-scale error-tolerant programmable interferometer fabricated by femtosecond laser writing

TL;DR

This paper presents the development and fabrication of the largest error-tolerant programmable 8-port interferometer using femtosecond laser writing, demonstrating broad wavelength operation for quantum photonics.

Contribution

It introduces a novel, error-tolerant architecture for programmable interferometers and fabricates the largest device of its kind with broad wavelength functionality.

Findings

Operates effectively from 920 to 980 nm wavelength range

Demonstrates error tolerance in a large-scale interferometer

Highlights potential for advanced quantum photonic applications

Abstract

We introduce a programmable 8-port interferometer with the recently proposed error-tolerant architecture capable of performing a broad class of transformations. The interferometer has been fabricated with femtosecond laser writing and it is the largest programmable interferometer of this kind to date. We have demonstrated its advantageous error tolerance by showing an operation in a broad wavelength range from $920$ to $980$ nm, which is particularly relevant for quantum photonics due to efficient photon sources. Our work highlights the importance of developing novel architectures of programmable photonics for information processing.