High-resolution spectral analysis of long single-frequency pulses generated by a self-sweeping Yb-doped fiber laser

Abstract

Continuous wave self-sweeping operation is demonstrated in a classical ring cavity configuration of Yb-doped fiber laser with a saturable absorber, which is usually used to obtain single-frequency lasing. Using heterodyne-based high-resolution spectral analysis we demonstrate that the laser generates a series of long (up to 1 ms) rectangular pulses consisting of single frequency radiation (the linewidth <0.7 MHz). At the same time, the lasing frequency changes between pulses regularly in a stepwise manner by one intermode beating frequency within a self-sweeping range of 100 pm. The effect of cavity configuration on pulse parameters (duration and chirp) is investigated. We also demonstrate that saturable absorbing mirrors design can be used to control the self-sweeping direction and value of the frequency jump.

Generation of tunable THz-radiation with self-sweeping Er-doped fiber laser

“…Such intensity dynamics solve both above mentioned problems of pulsed SSFL: the periods of silence disappear, and the signal accumulation time increases by 2-3 orders of magnitude. Such CW intensity dynamics has been demonstrated up to now in Yb (near 1064 nm [17]) and Er-doped (near 1560 [14] and 1600 [18][19] nm) SSFLs only. We decided to use an Er-doped CW SSL with generation near 1560 nm for THz radiation generation due to higher efficiency of the available THz generators and receivers.…”

“…Nevertheless, another type of the self-sweeping intensity dynamics -CW self-sweepinghas been demonstrated recently. In this case the intensity dynamics correspond to sequential generation of long (~500 μs and ~5 ms for Yb [17] and Erdoped [14,18,19] lasers, respectively) overlapping in time rectangular-shaped pulses, corresponding to sequential generation of equally spaced longitudinal modes. Such intensity dynamics solve both above mentioned problems of pulsed SSFL: the periods of silence disappear, and the signal accumulation time increases by 2-3 orders of magnitude.…”

“…The SSFL has CW intensity dynamics with relatively regular bursts at repetition period of several ms. It was demonstrated in papers [14,17], that the intensity bursts in CW SSFL dynamics correspond to the overlap of two longitudinal modes during the transition from one longitudinal mode to another, while intervals between the bursts correspond to the periods of SLM generation. Highfrequency intensity modulation presents during the bursts and corresponds to the value of frequency hops between sequentially generating longitudinal mods (12.1 MHz or double FSR of the SSFL cavity in our case).…”

Brillouin-like effects in rare-earth-doped bi-directional optical fiber amplifiers

“…The PIDG analog of the forward Brillouin scattering in optical fibers [66][67][68][69][70][71] could be of particular interest for further studies due to its enormous potential for practical applications in soliton fiber lasers as the method enabling the stabilization of harmonically mode-locked laser operation and super-mode noise reduction [72][73][74][75][76][77] . New mechanisms are important as well for designers of the Brillouin and random fiber lasers [78][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93] demanded in many applications in microwave photonics, data centers and atomic clocks. Translating the fiber system design to integrated photonics could dramatically reduce the footprint for many these applications 94-97 .…”

Модовая Динамика В Волоконных Лазерах С Динамической Распределенной Обратной Связью В Режиме Непрерывной Интенсивности Генерации

“…Такие импульсы мы стали называть прямоугольными. Через год был реализован иттербевый лазер [8], в котором динамика интенсивности также имеет квазинепрерывный характер с регулярными высокочастотными всплесками (см. Рис.1а).…”