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Main Authors: Johnson, Karl, Fedorov, Vladimir, Belogolovskii, Dmitrii, Grieco, Andrew, Rubin, Noah A., Fainman, Yeshaiahu
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2504.07300
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_version_ 1866910908217819136
author Johnson, Karl
Fedorov, Vladimir
Belogolovskii, Dmitrii
Grieco, Andrew
Rubin, Noah A.
Fainman, Yeshaiahu
author_facet Johnson, Karl
Fedorov, Vladimir
Belogolovskii, Dmitrii
Grieco, Andrew
Rubin, Noah A.
Fainman, Yeshaiahu
contents The modal dispersion of waveguides often limits integrated photonic devices to operation with a single polarization state. This presents a challenge for sensing and spectroscopy applications, which often require polarization diversity over wide bandwidths with high throughput. Here, we show that an unmodified thermally-driven silicon photonic Fourier transform spectrometer exhibits a polarization-separating effect in the frequency domain, even though only one polarization-insensitive detector is used. Using this effect, we experimentally demonstrate a simple on-chip spectrometer capable of extracting two-polarization spectra over a wide 1480-1630 nm bandwidth with a greater than 20 dB polarization extinction ratio. These specifications would be highly challenging to achieve using existing, conventional on-chip polarization-splitting techniques. We additionally demonstrate several improvements in calibration and testing that improve the performance of on-chip Fourier transform spectrometers even in the single-polarization case. The "interferometric modal splitting" principle which this spectrometer exemplifies is general to various on-chip spectrometer architectures, other spatial modes, and technologies other than thermally-driven Fourier transform spectrometers. Interferometric mode splitting shows promise as a general approach for robust and fundamentally broadband detection of orthogonal modes in guided-wave sensing.
format Preprint
id arxiv_https___arxiv_org_abs_2504_07300
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Interferometric modal splitting enables a broadband, dual-polarization on-chip spectrometer
Johnson, Karl
Fedorov, Vladimir
Belogolovskii, Dmitrii
Grieco, Andrew
Rubin, Noah A.
Fainman, Yeshaiahu
Optics
The modal dispersion of waveguides often limits integrated photonic devices to operation with a single polarization state. This presents a challenge for sensing and spectroscopy applications, which often require polarization diversity over wide bandwidths with high throughput. Here, we show that an unmodified thermally-driven silicon photonic Fourier transform spectrometer exhibits a polarization-separating effect in the frequency domain, even though only one polarization-insensitive detector is used. Using this effect, we experimentally demonstrate a simple on-chip spectrometer capable of extracting two-polarization spectra over a wide 1480-1630 nm bandwidth with a greater than 20 dB polarization extinction ratio. These specifications would be highly challenging to achieve using existing, conventional on-chip polarization-splitting techniques. We additionally demonstrate several improvements in calibration and testing that improve the performance of on-chip Fourier transform spectrometers even in the single-polarization case. The "interferometric modal splitting" principle which this spectrometer exemplifies is general to various on-chip spectrometer architectures, other spatial modes, and technologies other than thermally-driven Fourier transform spectrometers. Interferometric mode splitting shows promise as a general approach for robust and fundamentally broadband detection of orthogonal modes in guided-wave sensing.
title Interferometric modal splitting enables a broadband, dual-polarization on-chip spectrometer
topic Optics
url https://arxiv.org/abs/2504.07300