Raman-induced noiselike pulses in a highly nonlinear and dispersive all-fiber ring laser (original) (raw)
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We report on the observation of both stable dissipative solitons and noise-like pulses with the presence of strong Raman scattering in a relatively short all-normal-dispersion Yb-doped fiber laser. We show that Raman scattering can be filtered out by intracavity filter. Furthermore, by appropriate intracavity polarization control, the Raman effect can be utilized to generate broadband noise-like pulses (NLPs) with bandwidth up to 61.4 nm. To the best of our knowledge, this is the broadest NLP achieved in all-normal-dispersion fiber lasers
120nm Bandwidth noise-like pulse generation in an erbium-doped fiber laser
Optics Communications, 2008
We report on the generation of noise-like pulses with up to 120 nm bandwidth in a passively mode-locked erbium-doped fiber ring laser. By inserting a segment of slightly normal dispersion fiber in a mode-locked fiber laser cavity, we found that the spectrum of the noise-like pulse emission of the laser can be significantly broadened as a result of the four-wave-mixing and the soliton self-frequency shift effects in the inserted fiber.
Optics Express, 2005
We report experimental observations of stimulated Raman scattering in a standard fiber using a directly modulated DFB semiconductor laser amplified by two erbium-doped fibers. The laser pulse width was variably controlled on a nanosecond-scale; the laser emission was separated into two distinct regimes: an initial transient peak regime, followed by a quasi steady-state plateau regime. The transient leading part of the pump pulse containing fast amplitude modulation generated a broadband Ramaninduced spectral shift through the modulation instability and subsequent intra-pulse Raman frequency shift. The plateau regime amplified the conventional Stokes shifted emission expected from the peaks of the gain distribution. The output signal spectrum at the end of a 9.13 km length of fiber for the transient part extends from 1550 nm to 1700 nm for a pump pulse peak power of 65 W. We found that the Raman-induced spectral shift is measurable about 8 W for every fiber length examined, 0.6 km, 4.46 km, and 9.13 km. All spectral components of the broadband scattering appear to be generated in the initial kilometer of the fiber span. The Stokes shifted light generation threshold was higher than the threshold for the intra-pulse Raman-induced broadened spectra. This fact enables the nonlinear spectral filtering of pulses from directly modulated semiconductor lasers.
Noiselike pulses with a broadband spectrum generated from an erbium-doped fiber laser
Optics Letters, 1997
An erbium-doped f iber laser that produces a train of intense noiselike pulses with a broadband spectrum and a short coherence length is reported. The noiselike behavior was observed in the amplitude as well as in the phase of the pulses. The maximum spectral width obtained was 44 nm. The high intensity and the short coherence length of the light were maintained even after propagation through a long dispersive f iber. A theoretical model indicates that this mode of operation can be explained by the internal birefringence of the laser cavity combined with a nonlinear transmission element and the gain response of the f iber amplif ier.
Multibound soliton formation in an erbium-doped ring laser with a highly nonlinear resonator
IEEE Photonics Technology Letters
We have studied the generation of low-noise ultrashort multibound solitons in the telecommunication spectral window in an erbium-doped all-fiber ring laser with a highlynonlinear resonator mode-locked by a nonlinear polarization evolution effect. The multibound soliton generation is obtained with more than 20 bound dechirped pulses with a duration of ~ 240 fs at a repetition rate of ~ 11.3 MHz (with a signal-to-noise ratio of ~ 73.3 dB), the relative intensity noise is <-140 dBc/Hz, and the Allan deviation of the repetition frequency does not exceed ~1.3•10-8 with a time averaging window of ~ 100 s.
Journal of The Optical Society of America B-optical Physics, 2002
We present a combined experimental and theoretical study of the effect of pump pulse noise on the growth and statistics of multiorder stimulated Raman scattering in optical fiber. Because of the intensity dependence of stimulated Raman scattering, fluctuations in the detailed temporal structure of the pump pulse amplitude strongly affect the growth and statistics of the Stokes orders, even when dispersive effects are not important. By comparing experimental results with a detailed model including the frequency dependence of the Raman gain and the pump pulse temporal structure, we show that the pump pulse temporal fluctuations play a pivotal role in determining the growth and pulse energy statistics of the Stokes orders.
Scientific Reports, 2019
We report a study on the switching of the generation regimes in a high-powered thulium-doped all-fiber ring oscillator that is passively mode-locked with nonlinear polarization evolution technique with different pumping rates and cavity dispersion values. In one experimental setup, switching was observed between the noise-like pulse and the multi-soliton (in the forms of soliton bunches and soliton rain) regimes by the adjustment of the intracavity polarization controllers. We attributed this to the crucial influence of the nonlinear polarization evolution strength determined by such key parameters as saturation (over-rotation) power, linear phase bias, and nonlinear losses on the pulse evolution and stability. So the soliton collapse effect (leading to noise-like pulse generation) or the peak power clamping effect (generating a bunch of loosely-bound solitons) may determine pulse dynamics. Both the spectrum bandwidth and coherence time were studied for noise-like pulses by varying ...
Applied Optics, 2019
We experimentally investigate the alternative generation of dissipative solitons (DSs) or noise-like pulses (NLPs) from a passively mode-locked Er-doped all-fiber laser with 45° tilted fiber grating (45° TFG). The 45° TFG serves as an in-fiber polarizer for mode locking in the all-fiber laser cavity. Under the fixed orientations of the polarization controllers, flexible generation between DSs and NLPs can be precisely controlled by adjusting the pump power only. To the best of our knowledge, the total cavity length 4.92 m of our fiber laser is the shortest one among all of NLP fiber laser. We obtain the DS with 3 dB bandwidth of 20.4 nm centered at 1577 nm and the NLP with 3 dB bandwidth of 25.2 nm centered at 1574 nm. The fundamental repetition rate of the mode-locked pulses is 42.3 MHz. This DS-NLP switchable Er-doped fiber laser can be regarded as a multi-functional optical source for diverse practical and potential applications.