Compact, All-PM Fiber Integrated and Alignment-Free Ultrafast Yb:Fiber NALM Laser With Sub-Femtosecond Timing Jitter

• Published in: Journal of lightwave technology 2021-07, Vol.39 (13), p.4431-4438
• Main Authors: Ma, Yuxuan, Salman, Sarper, Li, Chen, Mahnke, Christoph, Hua, Yi, Droste, Stefan, Fellinger, Jakob, Mayer, Aline, Heckl, Oliver, Heyl, Christoph, Hartl, Ingmar
• Format: Article
• Language: English
• Subjects: Alignment; Bandwidth; Bragg gratings; Design parameters; Dispersion; Fiber lasers; Impact analysis; Laser mode locking; Laser noise; Lasers; Locking; Noise intensity; Optical fiber couplers; Optical fiber dispersion; optical frequency combs; Oscillators; OTHER INSTRUMENTATION; Power generation; Pulse duration; Radio frequency; Relative intensity noise; Timing jitter; Ultrafast optics; Vibration
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2021.3070208

We report a simple and compact design of a dispersion compensated mode-locked Yb:fiber oscillator based on a nonlinear amplifying loop mirror (NALM). The fully polarization maintaining (PM) fiber integrated laser features a chirped fiber Bragg grating (CFBG) for dispersion compensation and a fiber integrated compact non-reciprocal phase bias device, which is alignment-free. The main design parameters were determined by numerically simulating the pulse evolution in the oscillator and by analyzing their impact on the laser performance. Experimentally, we achieved an 88 fs compressed pulse duration with sub-fs timing jitter at 54 MHz repetition rate and 51 mW of output power with 5.5\times 10^{-5} [20 Hz, 1 MHz] integrated relative intensity noise (RIN). Furthermore, we demonstrate tight phase-locking of the laser's carrier-envelope offset frequency (f_{\text{ceo}}) to a stable radio frequency (RF) reference and of one frequency comb tooth to a stable optical reference at 291 THz.