Optical spectral asymmetry enables differential refractive-index sensing under near-perfect common-mode suppression in a single-cavity dual-comb fiber laser
Abstract
Single-cavity dual-comb fiber lasers offer near-perfect common-mode suppression, but such suppression is generally expected to eliminate differential sensing signals. Here we show that optical spectral asymmetry enables differential refractive-index (RI) sensing despite near-perfect common-mode suppression. By integrating an intracavity multimode interference (MMI) fiber sensor into a shared cavity, two counter-propagating combs are simultaneously generated and interrogated, enabling differential RI sensing based on the repetition-frequency difference (Δfrep). This architecture achieves near-perfect common-mode suppression, reducing temperature-induced drift by more than two orders of magnitude compared with a conventional dual-cavity dual-comb system. Spectral analysis reveals that optical spectral asymmetry gives rise to asymmetric repetition-frequency responses through cavity dispersion, thereby providing the physical origin of the differential sensing signal. A trade-off between sensitivity and noise suppression is identified: while the sensitivity is reduced due to the shared sensor, the improved frequency stability enhances robustness against environmental perturbations. These results demonstrate that near-perfect common-mode suppression does not preclude differential sensing, but instead reveals a new sensing mechanism governed by optical spectral asymmetry. These findings establish optical spectral asymmetry as a design principle for differential sensing in single-cavity dual-comb systems and provide a framework for highly stable long-term photonic sensing.
Related
- Cryogenic Optical Characteristics of S-FPL51 and S-LAH71: Refractive index, Transmission and Thermal expansion
- Dispersive-optical-model analysis of the asymmetry dependence of neutron skins
- Optical crosstalk suppression in micro-pitch mini-LED arrays via silicon grid integration
- Relative phase noise suppression for two-color optical sources via optoelectronic feedback and feedforward
- Experimental Investigation of Sub-aperture Spacing Effects on Scintillation Suppression in Multi-aperture Free-space Optical Communication under Atmospheric Turbulence
BibTeX
@misc{higaki2026optical,
title = {{Optical spectral asymmetry enables differential refractive-index sensing under near-perfect common-mode suppression in a single-cavity dual-comb fiber laser}},
author = {Masayuki Higaki and Yoshiaki Nakajima and Shuji Taue and Eiji Hase and Yu Tokizane and Takeshi Yasui},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.02150},
eprint = {2611.02150},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.02150},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Optical spectral asymmetry enables differential refractive-index sensing under near-perfect common-mode suppression in a single-cavity dual-comb fiber laser
AU - Masayuki Higaki
AU - Yoshiaki Nakajima
AU - Shuji Taue
AU - Eiji Hase
AU - Yu Tokizane
AU - Takeshi Yasui
PY - 2026
DA - 2026/11/01
PB - arXiv
DO - 10.48550/arxiv.2611.02150
UR - https://arxiv.org/abs/2611.02150
AB - Single-cavity dual-comb fiber lasers offer near-perfect common-mode suppression, but such suppression is generally expected to eliminate differential sensing signals. Here we show that optical spectral asymmetry enables differential refractive-index (RI) sensing despite near-perfect common-mode suppression. By integrating an intracavity multimode interference (MMI) fiber sensor into a shared cavity, two counter-propagating combs are simultaneously generated and interrogated, enabling differential RI sensing based on the repetition-frequency difference (Δfrep). This architecture achieves near-perfect common-mode suppression, reducing temperature-induced drift by more than two orders of magnitude compared with a conventional dual-cavity dual-comb system. Spectral analysis reveals that optical spectral asymmetry gives rise to asymmetric repetition-frequency responses through cavity dispersion, thereby providing the physical origin of the differential sensing signal. A trade-off between sensitivity and noise suppression is identified: while the sensitivity is reduced due to the shared sensor, the improved frequency stability enhances robustness against environmental perturbations. These results demonstrate that near-perfect common-mode suppression does not preclude differential sensing, but instead reveals a new sensing mechanism governed by optical spectral asymmetry. These findings establish optical spectral asymmetry as a design principle for differential sensing in single-cavity dual-comb systems and provide a framework for highly stable long-term photonic sensing.
ER -