English

DC response of an interferometer topology with an L-shaped cavity: a tabletop study

Instrumentation and Detectors 2026-01-21 v2 Instrumentation and Methods for Astrophysics General Relativity and Quantum Cosmology Optics

Abstract

A new interferometer topology for kilohertz gravitational-wave detection was recently proposed in [Zhang et al. Phys. Rev. X 13, 021019 (2023)]. The design is based on an L-shaped optical cavity pumped through a Sagnac-like vortex. We report a tabletop experiment that characterizes the interferometer's optical response near DC. When the laser frequency is locked to the resonance of the L-shaped cavity, we observe that the cavity input coupler becomes effectively transparent, yielding a simple Michelson-like response. Moreover, the Sagnac vortex separates into upper and lower paths, which behave as two independent pumping paths driving the cavity. These observations are in agreement with theoretical predictions. Our results provide an intuitive physical picture of this interferometer topology and offer insight into its lock acquisition strategy.

Keywords

Cite

@article{arxiv.2601.09764,
  title  = {DC response of an interferometer topology with an L-shaped cavity: a tabletop study},
  author = {Junlang Li and Jiehong Huang and Xinyao Guo and Haixing Miao and Yuchao Chen and Xiaoman Huang and Yuan Pan and Chenjie Zhou and Raffaele Flaminio and Jameson Graef Rollins and Bram Slagmolen and Fan Zhang and Teng Zhang and Mengyao Wang},
  journal= {arXiv preprint arXiv:2601.09764},
  year   = {2026}
}

Comments

According to the organization's regulations, papers that have not been fully reviewed within the organization cannot be published on arXiv. However, due to our oversight, it was mistakenly published. Once the internal review process is complete, it will be re-uploaded