Universal quantum frequency comb measurements by spectral mode-matching

TL;DR

This paper introduces a novel spectral mode-matching technique enabling arbitrary, one-shot measurements of multimode quantum optical sources, overcoming limitations of traditional homodyne detection for quantum information processing.

Contribution

It presents the first general formalism and implementation proposal for spectral mode-matching in quantum measurements, enhancing capabilities for photonic quantum computing.

Findings

Developed a complete formalism for spectral mode-matching

Proposed implementation using microcavity arrays

Enables arbitrary, one-shot measurements of multimode quantum states

Abstract

The frequency comb of a multimode interferometer offers exceptional scalability potential for field-encoded quantum information. However, the staple field detection method, homodyne detection, cannot access quantum information in the whole comb because some spectral quadratures (and their asymmetries with respect to the LO) are out of reach. We present here the first general approach to make arbitrary, one-shot measurements of a multimode quantum optical source, something that is required for photonic quantum computing and is not possible when using homodyne detection with a pulse-shaped LO. This approach uses spectral mode-matching, which can be understood as interferometry with a memory effect. We derive a complete formalism and propose an implementation by microcavity arrays.