From Event: International Conference on Space Optics — ICSO 2021, 2021
Mode-locked lasers, and in particular solid-state femtosecond lasers, are oscillators with a unique physics capable to exhibit extremely low-phase noise of the emitted pulse train. Here we report ultra-low phase noise microwave generation with a self-referenced, fully-stabilized mode-locked femtosecond laser. The system involves a 395-MHz repetition rate 1560nm laser which is self-referenced and whose repetition rate is locked to a cavity-stabilized continuous-wave laser. The selfreferencing is achieved with a f-3f nonlinear interferometer realized in a silicon nitride highly-nonlinear waveguide. Prior to optical-to-electrical conversion for X-band microwave generation, the 395-MHz repetition rate of the mode-locked laser pulse train is multiplied in a fiber interleaver to 3.16 GHz. A high-power handling photodiode converts the optical pulse train to an electrical frequency comb with 3.16 GHz frequency spacing. Finally, the 9.5-GHz harmonics is bandpassfiltered and phase noise measurements have shown a record-low phase noise floor of -175 dBc/Hz at 1-MHz offset frequency.
© (11 June 2021) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
L. Karlen, N. Torcheboeuf, S. Kundermann, T. Herr, E. Obrzud, V. Brasch, F. Schaub, H. Meier, A. Stroganov, M. Geiselmann, and S. Lecomte, "Photonics-based ultra-low phase noise X-band microwave generation," Proc. SPIE 11852, International Conference on Space Optics — ICSO 2020, 1185246 (Presented at International Conference on Space Optics — ICSO 2021: 11 June 2021; Published: 11 June 2021); https://doi.org/10.1117/12.2599641.