Skip to main content

Research Repository

Advanced Search

Frequency spectrum of an optical resonator in a curved spacetime

Rätzel, Dennis; Schneiter, Fabienne; Braun, Daniel; Bravo, Tupac; Howl, Richard; Lock, Maximilian P.E.; Fuentes, Ivette

Frequency spectrum of an optical resonator in a curved spacetime Thumbnail


Dennis Rätzel

Fabienne Schneiter

Daniel Braun

Tupac Bravo

Richard Howl

Maximilian P.E. Lock

Ivette Fuentes


The effect of gravity and proper acceleration on the frequency spectrum of an optical resonator—both rigid or deformable—is considered in the framework of general relativity. The optical resonator is modeled either as a rod of matter connecting two mirrors or as a dielectric rod whose ends function as mirrors. Explicit expressions for the frequency spectrum are derived for the case that it is only perturbed slightly and variations are slow enough to avoid any elastic resonances of the rod. For a deformable resonator, the perturbation of the frequency spectrum depends on the speed of sound in the rod supporting the mirrors. A connection is found to a relativistic concept of rigidity when the speed of sound approaches the speed of light. In contrast, the corresponding result for the assumption of Born rigidity is recovered when the speed of sound becomes infinite. The results presented in this article can be used as the basis for the description of optical and opto-mechanical systems in a curved spacetime. We apply our results to the examples of a uniformly accelerating resonator and an optical resonator in the gravitational field of a small moving sphere. To exemplify the applicability of our approach beyond the framework of linearized gravity, we consider the fictitious situation of an optical resonator falling into a black hole.


Rätzel, D., Schneiter, F., Braun, D., Bravo, T., Howl, R., Lock, M. P., & Fuentes, I. (2018). Frequency spectrum of an optical resonator in a curved spacetime. New Journal of Physics, 20(5), Article 053046.

Journal Article Type Article
Acceptance Date Apr 27, 2018
Online Publication Date May 18, 2018
Publication Date May 18, 2018
Deposit Date Dec 6, 2018
Publicly Available Date Dec 7, 2018
Journal New Journal of Physics
Publisher IOP Publishing
Peer Reviewed Peer Reviewed
Volume 20
Issue 5
Article Number 053046
Public URL
Publisher URL


Downloadable Citations