Spectral Transfer of Coherence with fiber-based interferometer
Principal Investigator : Dr Fabien Kéfélian
Fundings : Provence-Alpes-Côte d'Azur region, First-TF network, Observatoire de la Côte d'Azur & Université de Nice
Summary :The goal of this project is to investigate experimentaly the potential of fiber based large arm imbalence interferometer to transfer the coherence of a stable laser to a laser with a wavelength difference of several tens of nanometers.PhD subject 2020
Former investigator : Dr Frédéric Audo, FIRST-TF funded post-doctoral research fellow in 2016, Lin-Wei Yu, intern from SupOptique - Institut d'optique graduate school in summer 2016
Current Results :
First experimental evidence of a white frequency noise floor due to the residual third order nonlinearity of an optical frequency discriminator in laser frequency stabilization
We have developped a low noise system to measure the frequency noise floor of the locking of a laser ona fiber-based large imbalence interferometer. Thanks to this experiment we have been able to detect a significant contribution of the third order residual nonlinearity of the Michelson interferometer at the 100 mHz/Hz^1/2 level. The white noise level measured is in good agreement with the result of a numerical simulation of the effect of the non-linear frequency discriminator.
This is to our knowledge the first time that the effect of the residual non linearity of an optical frequency discriminator for frequency stabilization is considered and experimentaly measured. This effect could set the limit of the spectral linewidth of a laser stabilized on an ultra-stable Fabry-Perot cavity.
Publications and communications :
- Experimental evidence of a fundamental noise floor at the tens of millihertz level in laser locking onto unbalanced fibre-based Michelson interferometer, , F. Audo, J.-P. Coulon and F. Kéfélian, CLEO Europe/EQEC 2017
- Experimental evidence of a frequency noise floor at 0.1 Hz/Hz^0.5 in laser locking onto Michelson fiber based interferometer, F. Audo, J.-P. Coulon and F. Kéfélian, annual general assembly of the network of excellence First-TF (Network for Research, Innovation, Education, Services and Training in Time-Frequency, "LABEX") 08/06/17