18 October 2017
SYRTE Laboratory has for several years developed a frequency stabilization project of infrared lasers on atomic vapor, in compact and fibered configurations. This development is based on Telecom photonic components in the vicinity of 1.5 µm, which exhibit superior technological readiness level, unequaled at other wavelength range.
The targeted frequency stability is of order of a few 10-14 for the short term and few 10-15 on the medium / long term. This level of performance is typically that required for several space missions dedicated to the detection of gravitational waves in space or to the earth gravitational field measurements...
For the frequency stabilization purpose, we use very narrow and intense hyperfine iodine lines in the green range which exhibit have quality factors Q> 109. To bridge the frequency gap between Telecom and green ranges of the optical domains, we have operated a very efficient frequency tripling process based on Lithium Niobate waveguide crystals. A nonlinear optical conversion efficiency P3w/Pw > 36 %, is already demonstrated with a total power consumption of less than 20 W. This result is the best efficiency ever demonstrated for a CW frequency tripling process. 300 mW of harmonic power is generated at 514 nm from a fundamental optical power of 800 mW at 1.54 µm.
Following this development, a compact laser spectroscopy optical setup, based on a short sealed quartz cell which contains the molecular iodine vapor, was built to stabilize the IR laser frequency. A frequency stability at the level of 4.5 x 10-14t-1/2 with a minimum value of 6 x 10-15 from 50 s to 100 s is demonstrated.
Contact
Ouali Acef
- Email: ouali.acef (at) obspm.fr
- Tel.: +33 (0) 1 40 51 20 50