Low noise, self-referenced all polarization maintaining Ytterbium fiber laser frequency comb

Abstract

We report the implementation of a self-referenced optical frequency comb generated by a passively mode-locked all polarization maintaining (PM) Yb fiber laser based on a nonlinear amplifying loop mirror (NALM). After spectral broadening the optical spectrum spans from 650 nm to 1400 nm, allowing for the generation of an optical octave and carrier envelope offset frequency (f) stabilization through a conventional f-2f interferometer. We demonstrate for the first time the stabilization of the f of such a PM Yb system with an in-loop fractional frequency stability scaled to an optical frequency of low 10 at 1 second averaging time, offering a great potential for applications in optical atomic clock metrology.

Flexible all-PM NALM Yb:fiber laser design for frequency comb applications: operation regimes and their noise properties

“…In contrast to other implementations of the figure-9 concept that featured a fixed splitting ratio k at the loop entrance [29,30,33,38], the splitting ratio in our case varies as a function of the wave plate positions. The normalized field vector at the entrance of the loop is…”

“…In particular, they have raised considerable interest as sources of low-noise optical frequency combs: full frequency comb stabilization (i.e. stabilization of both the carrier-envelope offset frequency f CEO and comb repetition rate f rep ) has been shown in Er-based configurations [30,37], whereas f CEO -stabilization has also been reported in an Yb-based system [38,39]. Furthermore, even all-PM NALM-based dual-comb configurations have been demonstrated, where the two pulse trains are generated within the same laser cavity [40][41][42].…”

Ultralow Noise Optical Frequency Combs

“…For traditional Ti:sapphire lasers, the pump power is typically modulated by an AOM [16]- [18]. Pump current modulation is often used for LD-pumped mode-locked laser such as Ti:sapphire [19], Yb [22]- [26], [33], [41]- [43], [87] or Er [28], [35]- [38], [44], [49]- [52], [55], [77], [83], [84], [88]- [93] lasers. For these pump power modulation methods, the feedback bandwidth is limited by the stimulated gain lifetime.…”

Tailored Design of Mode-Locking Dynamics for Low-Noise Frequency-Comb Generation

“…In contrast, Ybfiber lasers surpass Er-fiber lasers in almost every technical metric, such as power, power efficiency, pulse energy, and minimum-achievable pulse duration. Despite these advantages, few frequency combs based on Yb-fiber lasers have been demonstrated [14][15][16][17][18][19][20][21][22], in contrast to hundreds of reports of the use of Er-fiber lasers. Even though excellent results were demonstrated in Ref.…”

“…Follow-up studies on Yb-fiber combs have, in contrast, achieved more modest performance, including pulse durations exceeding 100 fs. Furthermore, none of these [14][15][16][17][18][19][20][21][22] were used to make absolute-frequency measurements or were used in an application after being linked to an absolute-frequency reference.…”