Reverse spontaneous laser line sweeping in ytterbium fiber laser

Abstract

Self-induced laser line sweeping of various regimes of sweep direction is reported for an experimental ytterbium fiber laser. The regimes involve sweeping from shorter to longer wavelengths (1076 nm 1083 → nm)-so-called normal self-sweeping; from longer to shorter wavelengths (1079 nm 1073 → nm)-so-called reverse self-sweeping; and a mixed regime in which a precarious balance of the normal and reverse sweeping exists and the sweep direction can change between consecutive sweeps. The regimes of sweeping were selected by changing the pump wavelength only. A detailed explanation of this sweep direction dynamics is presented based on a semi-empirical model. This model also provides a way to predict the sweep direction of fiber lasers based on other rare-earth-doped laser media.

Self-sweeping ytterbium-doped fiber laser based on a fiber saturable absorber

“…Describing in detail the generation and annihilation in the self-sweeping regime later [9,10]. SSFL reported only in YDF pushes the researcher to attempt in different doped fibers [11][12][13].…”

“…Nowadays, the research on the self-sweeping effect has involved many phenomena. The sweeping direction can be defined by the normal selfsweeping and reverse self-sweeping in which the generated wavelength increases and decreases in the sweeping range, respectively [21]. The self-sweeping fiber laser in the linear cavity has produced multiple sweeping directions involving normal selfsweeping, reverse self-sweeping and a mixed state [22,23].…”

“…11,12) SSFL reported only in YDF pushes the researcher to attempt in different doped fibers. [13][14][15] Subsequently, neodymium-, bismuth-, erbium-, thulium-holmium-, holmium-, and thulium-doped fiber serve as active media, all of which can obtain the self-sweeping regime with broadly sweeping ranges. [16][17][18][19][20][21] Besides, the SSFL with single frequency signals displays the remarkable features in the spectrum and intensity dynamics.…”

Recent Progress and Development Trend of Self-Sweeping Fiber Laser

“…In 2017, Ref. [22] achieved the first reverse self-sweeping effect of an ytterbium-doped fiber laser. In this experiment, the wavelength sweeping direction was divided into two categories, the normal self-sweeping direction, which refers to the shift of the output wavelength from short to long wavelengths, and the reverse self-sweeping direction, which refers to the shift of the output wavelength from long to short wavelengths.…”

“…FIGURE 3 | Three spectral dynamics observed by Yb-doped self-sweeping fiber laser in 2017[22]. Normal self-sweeping (blue curve); Mixed self-sweeping (green curve); Reverse self-sweeping (red curve).…”