High-performance mirrors with ultralow optical absorption and minimal Brownian noise are key ingredients for the construction of optical atomic clocks, compact optical reference cavities and stabilized lasers, as well as the next generation of gravitational wave detectors. The high-quality-factor single-crystal coatings used in our xtal stable™ optics substantially reduce inherent thermo-mechanical fluctuations, enabling a significant improvement in the overall frequency stability of precision interferometers. We are extremely excited to have our mirrors employed in groundbreaking experiments and cutting edge commercial systems pushing the ultimate limits of laser linewidth and cavity noise performance.
< 1 ppm
< 5 ppm
Radius of curvature
> 10 cm
- Typically >99.99%, >99.999% achievable
- Loss angle
- <4 × 10⁻⁵ at 300 K, <5 × 10⁻⁶ at 10 K
- Temperature range
- Cryogenic, room temperature, and high temperature solutions available
- Coating material
- Single-crystal GaAs/AlGaAs
- Coating surface quality
- 1 Å RMS micro-roughness
- Substrate material
- Typically fused silica, other materials available
- Substrate diameter
- 0.5 - 1 inch (12.7 - 25.4 mm), other sizes available
- Surface flatness
- <0.10 wave P-V measured @ 633 nm
- Similar to fused silica, cleaning instructions provided on request
- Data Sheet
- Click here to download the xtal stable specifications sheet
Cavity Assembly Service from CMS
CMS now offers optical contacting services for your complete reference cavity needs! Customers can supply their own spacer and ULE compensation rings, or optionally, provide specifications for procurement through our trusted network of vendors.
All completed Fabry-Perot cavities are tested in their final configuration, ensuring that customers receive a fully-functional reference cavity ready for immediate integration.
Contact CMS to discuss your requirements and how we can deliver the complete system to you.
Applications for xtal stable mirrors
Precise Atomic Clocks
Low-temperature optical reference cavities using crystalline mirror technology are currently being tested and represent a new world-record in frequency stability. The expected stability surpasses the previously unattainable level of Δf/f below 10¹⁷ in one of second integration time and will establish a new milestone in the performance of optical atomic clocks.
Optical Reference Cavities
Crystalline mirror technology allows for a significant reduction in the size of optical reference cavities, while simultaneously maintaining excellent noise performance. As a consequence, compact, space-based optical reference cavities are currently being developed. This serves as a primer for future space-based navigation systems using optical reference standards.
Gravitational Wave Detection
Crystalline coatings allow, for the first time, for the operation of laser-based interferometric gravitational wave detectors at the ultimate (standard) quantum limit. This goes hand-in-hand with a significant increase in the volume of observed space in a gravitational wave observatory. At this stage, large area-diameter crystalline coatings are being employed both at the German 10 meter prototype detector and the Australian 80 meter prototype detector, and further noise tests are underway at LIGO.
Please contact CMS for more information about all our products. For example, part number 1064-10-254-FS10PAR is a 1064 nm HR crystalline coating on super-polished fused silica with a 1″ diameter, 1/4″ thick, planar / planar fused silica substrate, with backside AR coating and full-face HR centered at 1064 nm. Contact us for more details!