Witnessing the pulse birth—transient dynamics in a passively mode-locked femtosecond laser

Abstract

High temporal resolution measurements of the output of an Yb:KYW femtosecond laser, recorded immediately after opening the laser cavity, give an insight into the transient laser dynamics. The evolution of the light intensity measured with linear and nonlinear detectors, together with the time-resolved laser spectrum were measured and the process of the mode-locking onset was investigated. A phenomenological model of the laser dynamics has been developed that reproduces the experimental results.

Real-time full-field characterization of transient dissipative soliton dynamics in a mode-locked laser

“…1(c) shows measurements in the stable mode-locked regime using 30 GHz detection, to illustrate a regular pulse train of constant intensity. Of course, such complex transient dynamics have been seen in both numerical and experimental studies of a range of other passively-modelocked lasers (27)(28)(29)(30)(31)(32)(33)(34), but we include these measurements here for completeness. The key point is that, even with a detection bandwidth of 30 GHz, the temporal width of the pulses seen in the photodiode intensity record is ~30 ps, precluding any detailed study of the underlying soliton dynamics in the transient regime.…”

Dynamics of carbon nanotube-based mode-locking fiber lasers

“…Despite the stable pulse train formed through mode-locking, the initial buildup process of pulses is highly random and nonrepetitive [5,220]. Since the 1990s, the nonlinear dynamics of mode-locked lasers has been reported by researchers through a large number of experiments and theories, with the emphasis being on self-starting [221][222][223][224][225][226]. In the stationary state, the soliton train generated from mode-locked lasers can be described theoretically by means of the generalized nonlinear Schrödinger equation (GNLSE) or the Ginzburg-Landau equation (GLE) [17], many interesting phenomena and soliton operation had been reported in a variety of laser configurations.…”

Observing the spectral dynamics of a mode-locked laser with ultrafast parametric spectro-temporal analyzer

“…the self-starting mode-locking; the spectral dynamics of ultrafast events is largely unexplored owing to the lack of high-speed spectrum analyzer [5][6][7][8]. Techniques such as imaging grating spectrometer with beam scanner [5], gating photomultiplier tube (PMT) associated with monochrometer [6] and framing streak camera coupled with spectrograph [7], have been introduced to investigate the self-starting spectral transitions of a mode-locked laser [8]. These devices, unfortunately, have to be synchronized with the event to be observed, or operated in burst mode can only provide several frames per acquisition.…”