Gouy phase shift measurement in a high-finesse cavity by optical feedback frequency locking

Abstract

We demonstrate a simple and robust scheme to measure the relative position of transverse cavity modes with high precision. This is based on robust optical-feedback frequency locking of a diode laser to a cavity resonance. A fraction of the laser power is then frequency shifted and used to re-inject other cavity resonances to obtain their positions relative to the locking resonance. This delivers the Gouy phase shift of the cavity modes with precision down to 6.4 × 10 −8 rad, comparable to previous state of the art based on a more complex setup. This should also be of interest for high precision/accuracy measurement of distance and displacement.

Resonance of Vector Vortex Beams in a Triangular Optical Cavity

“…We hipothesize that this small displacement is due to the birefringence of dielectric thin layers that constitute the cavity mirrors (as in Ref. 46 ).…”

Optical cavity spectroscopy using heterodyne detection with optical feedback laser frequency locking

“…OF fast and efficient locking of a semiconductor laser to an optical cavity has been exploited to perform absorption spectroscopy of gas samples with high sensitivity for trace analysis applications [7,8]. It was also exploited to obtain other types of sensitive measurements in optics such as birefringence effect [9] or polarisation mode splitting [10].…”

“…In other words, we detect the RF beating signal between the laser locking mode and the injected side band at cavity transmission by using a fast photodiode. Specifically, the laser-cavity frequency locking is obtained by optical feedback (as done in [10]), but other locking schemes have been used, such as the well-known Pound-Drever-Hall method [5], in other approaching setups [1,11,12]. It should be noted that OF locking is particularly adapted to a V-shaped cavity geometry, but it can also be implemented with linear cavities [9,13,14].…”