Microwave photonics

All optical microwave generation (contact Yann Kersalé)

We use femtosecond-laser frequency combs to generate ultra-low noise microwave signals.

An optical frequency comb is a wonderful tool  to link the optical and microwave frequency ranges.

We have shown, with our collegues from the LNE SYRTE- Observatoire de Paris, that the comb noise, used as a frequency divider to generate a 10 GHz carrier,  can be as low as -120 dBc/Hz at 1 Hz  leading to a relative frequency stability of the order of  1.10-16 τ-1/2

We have used this frequency comb to characterize the residual phase noise of the laser stabilized on the spherical cavity. We obtained a single side band phase noise of  L(f) = -104 dBc/Hz at 1 Hz offset frequency for a 10 GHz carrier.

Refs:

Ultra-low noise microwave extraction from fiber-based optical frequency comb, J. Millo et al., Optics Letters 34, 3707-3709, 2009.

Sub-100 attoseconds Optics-to-microwave synchronization, W. Zhang et al., Applied Physics Letters 24, 025102, 2010.

Advanced noise reduction techniques for ultra-low phase noise optical-to-microwave division with femtosecond fiber combs, W. Zhang et al., IEEE Trans. on UFFC 58, 900-908, 2011.

Ultra-low phase noise all-optical microwave generation setup based on commercial devices, A. Didier et al., Applied Optics 54, 3682-3686, 2015.