Broadband multimode fiber spectrometer

TL;DR

This paper presents a versatile all-fiber spectrometer that combines a wavelength division multiplexer with multimode fibers, achieving high resolution and broad bandwidth, along with an efficient spectrum reconstruction algorithm.

Contribution

It introduces a novel all-fiber spectrometer design that overcomes traditional trade-offs and includes an algorithm for accurate spectrum reconstruction from speckle patterns.

Findings

Achieved 100 nm bandwidth with 0.03 nm resolution at 1500 nm

Developed an efficient algorithm for spectrum reconstruction from speckle patterns

Demonstrated rapid and accurate spectrum recovery for various spectral types

Abstract

A general-purpose all-fiber spectrometer is demonstrated to overcome the trade-off between spectral resolution and bandwidth. By integrating a wavelength division multiplexer with five multimode optical fibers, we have achieved 100 nm bandwidth with 0.03 nm resolution at wavelength 1500 nm. An efficient algorithm is developed to reconstruct the spectrum from the speckle pattern produced by interference of guided modes in the multimode fibers. Such algorithm enables a rapid, accurate reconstruction of both sparse and dense spectra in the presence of noise.