Optical Resonators in Current and Future Experiments of the ALPS Collaboration

TL;DR

The paper discusses the design, limitations, and potential improvements of optical resonators used in the ALPS 'light shining through a wall' experiment to enhance detection sensitivity for weakly interacting particles.

Contribution

It provides detailed analysis of current resonator setups and proposes the integration of a regeneration resonator with single-photon detection for future experiments.

Findings

Enhanced sensitivity with large-scale production resonator

Limitations identified in current resonator configurations

Proposed integration of regeneration resonator with SPC detector

Abstract

The ALPS collaboration runs a "light shining through a wall" (LSW) experiment to search for weakly interacting sub-eV particles (WISPs). Its sensitivity is significantly enhanced by the incorporation of a large-scale production resonator and a small-scale high-power resonant second harmonic generator. Here we report on important experimental details and limitations of these resonators and derive recommendations for further experiments. A very promising improvement for a future ALPS experiment is the incorporation of an additional large-scale regeneration resonator. We present a rough sketch of how to combine a regeneration resonator with a single-photon counter (SPC) as detector for regenerated photons.