Dual-wavelength quasi-mode-locked regimes of an Er-doped fiber ring laser (original) (raw)
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Optical Fiber Technology, 2008
We identify the spectral gain filtering as a mechanism of multiple pulse formation in a fiber laser passively mode-locked through nonlinear polarization rotation operating in the normal dispersion regime. A correlation is theoretically established between the spectral gain bandwidth and the possibility for the laser to deliver several pulses by cavity round-trip: narrow spectrum favours multiple pulsing. Moreover the model allows to show that spectral loss or gain filtering are equivalent with respect to their consequences on the multiple pulsing regime. Experimental results obtained with an erbium-doped fiber laser and an ytterbium-doped fiber laser confirm the theoretical calculations. In addition, an indirect confirmation of the influence of the spectral filtering is proposed using an experimental setup involving a unique laser.
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.
Applied optics, 2016
We report on the stable picosecond and femtosecond pulse generation from the bidirectional erbium-doped all-fiber ring laser hybridly mode-locked with a coaction of a single-walled carbon nanotube-based saturable absorber and nonlinear polarization evolution that was introduced through the insertion of the short-segment polarizing fiber. Depending on the total intracavity dispersion value, the laser emits conservative solitons, transform-limited Gaussian pulses, or highly chirped stretched pulses with almost 20 nm wide parabolic spectrum in both clockwise (CW) and counterclockwise (CCW) directions of the ring. Owing to the polarizing action in the cavity, we have demonstrated for the first time, to the best of our knowledge, an efficient tuning of soliton pulse characteristics for both CW and CCW channels via an appropriate polarization control. We believe that the bidirectional laser presented may be highly promising for gyroscopic and other dual-channel applications.
Birefringence-Induced Trains of High-Rate Pulses in a Mode-Locked Fiber Laser
2009
The output of a mode-locked erbium-doped ring fiber laser incorporating a section of a polarization-maintaining (PM) fiber is investigated in both numerical simulations and experiments. With proper inline polarization control, the laser can be set to emit a train of pulses, separated by the differential group delay of the PM section. Repetition rates as high as 500 GHz are experimentally
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.
Dual Orthogonal Polarization States in an Active Mode-Locked Birefringent Fiber Ring Laser
IEEE Photonics Technology Letters, 2000
We report the generation of dual amplitude pulses in an active mode-locked fiber laser within a birefringent cavity. Different to normal mode-locked pulses with identical amplitude and polarization state, and pulses polarized on both x-and y-axes simultaneously exist in the output pulse train. The two orthogonal pulse sequences have different amplitudes and lase at different wavelengths. Dual wavelengths are the result of red shift and blue shift of the x-and y-polarization states of the generated pulses, respectively, due to the detuning phenomena. Locking to individual x-or y-polarized pulse is also obtained by adjusting polarization controllers.
Quantum Electronics, 2013
We report an all-fibre ultrashort pulse erbium-doped ring laser passively mode-locked by single-wall carbon nanotubes dispersed in carboxymethylcellulose-based polymer films. Owing to intracavity dispersion management and controlled absorption in the polymer films, the laser is capable of generating both femto-and picosecond pulses of various shapes in the spectral range 1.53-1.56 mm. We have demonstrated and investigated the generation of almost transform-limited, inversely modified solitons at a high normal cavity dispersion.
Broadband output from an actively mode-locked fiber ring laser
Applied Optics, 2009
Nonlinear effects are invoked with the inclusion of a dispersion shifted fiber in the cavity of an actively mode-locked erbium-doped fiber ring laser. The spectrally broadened output is analyzed both in the time and the spectral domains for different lengths of this specialty fiber. A maximum spectral width of 52 nm is achieved at a pump power of 180 mW under optimized conditions in this configuration.