26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

Towards a Self-Referenced Optical Cavity Using Temperature-Induced Diamond Birefringence

Not scheduled

20m

Belinda Hutchinson Building (The University of Sydney )

Poster ANZOS | Photonics and Optics (ANZCOP)

Description

Abstract
Ultra-stable lasers are essential for optical atomic clocks, quantum sensors, precision spectroscopy, and navigation systems. Current state ofthe art frequency stabilisation techniques mainly rely on cryogenic reference cavities to suppress temperature and vibrational variation.
While these approaches are highly effective, it also increases system complexity and limit the development of compact and transportable optical systems. Therefore, it is essential to investigate alternative ways to miniaturise these laser systems.
In this work, we investigate a self-referenced cavity architecture based on temperature dependent birefringence in diamond. Thermal variations within the crystal can generate stress induced refractive index anisotropy, leading to frequency splitting between orthogonal polarisation modes. Monitoring this differential frequency shift provides an intrinsic measurement of temperature fluctuations and offers a pathway for compensating thermally induced frequency drift without requiring an external reference cavity.
A Fabry Perot cavity operating at 1018 nm has been developed to investigate polarisation mode splitting under controlled thermal conditions. The cavity transmission is monitored while the intracavity crystal temperature is varied, enabling measurement of frequency splitting between orthogonal polarisation modes. Preliminary measurements using birefringent crystals like LBO have been used to establish the experimental methodology and verify the sensitivity of the cavity to temperature-dependent polarisation splitting. These measurements provide a framework for extending the technique to diamond, where stress-induced birefringence is expected to produce experimentally resolvable frequency shifts.
The long-term objective is the development of a compact self-referenced laser system in which diamond simultaneously acts as the sensing element and lasing material. Such an approach may enable robust and transportable frequency references for next generation quantum technologies, optical clocks, and precision metrology.