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Passively Q-switched and mode-locked Tm-Ho co-doped fiber laser using a WS2 saturable absorber fabricated by chemical vapor deposition
摘要： We demonstrate a passively Q-switched and mode-locked Tm-Ho co-doped fiber laser based on a WS2 saturable absorber (SA) fabricated by chemical vapor deposition method. When the pump power increases from 0.32 W to 0.38 W, the repetition rate of the Q-switched laser pulse increases 47.1 kHz to 90.1 kHz and the pulse width decreases from 6.2 μs to 1.7 μs. In addition, the mode-locking operation can also be observed by adjusting the polarization controller (PC) and mode-locked laser pulses at 1883.2 nm can be achieved at a high pump power between 0.5 W and 0.64 W. The pulse duration is 1.07 ns and repetition rate is 23.8 MHz and the pulse is the longest mode-locked pulse with WS2-SA ever reported.
关键词： Mode-locked lasers,Optical fiber lasers,Ultrafast optics
更新于2025-11-28 14:24:03
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Dual-wavelength passively mode-locked Yb-doped fiber laser based on a $\text{SnSe}_2$-PVA saturable absorber
摘要： In this paper, tin diselenide (SnSe2) was successfully prepared with liquid phase exfoliation method and embedded into polyvinyl alcohol (PVA) as a saturable absorber (SA) in a dual-wavelength passively mode-locked Yb-doped fiber laser. Stable mode-locked pulses with a maximum average output power of 2.55 mW and a slope efficiency of 1.3% at the fundamental repetition rate of 333 kHz were achieved. By properly adjusting polarization state, four kinds of dual-wavelength fundamental frequency mode-locked pulses with peak wavelength intervals of 0.4, 1.0, 1.5 and 1.9 nm were obtained, and corresponding waveforms with different single pulse shapes were investigated in our work. A maximum signal to noise ratio (SNR) of 71.04 dB indicates that SnSe2 is promising to serve as SA in passively mode-locked fiber lasers.
关键词： Fiber lasers,Mode-locked lasers,Diode-pumped lasers
更新于2025-11-28 14:23:57
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Generation of J-shaped pulses in ultra-long Ytterbium doped mode locked fiber laser
摘要： We report, for the first time, generation of J-shaped pulses in figure-eight type ultra-long, all-normal dispersion Ytterbium-doped fiber laser mode locked by the combined effect of nonlinear polarization evolution and nonlinear optical loop mirror. Cavity birefringence based spectral filtering introduced by polarization controllers is used for the formation of J-shaped as well as step-like and flat-top pulses. The shape and duration of generated pulse is found to depend on applied birefringence as well as pump power. J-shaped pulses of 180 ns duration and 332 nJ pulse energy at 201.45 kHz fundamental repetition rate are generated at 200 mW pump power. Experimentally, a strong correlation between spectral and temporal profile of the generated pulse shapes is established where it has been shown that asymmetric spectral filtering is responsible for generation of J-shaped and step-like pulses. Numerically, the spectral transmission of figure-eight type resonator under different cavity birefringence and intra-cavity power is investigated which qualitatively supports the experimental results.
关键词： mode locked lasers,Ytterbium doped fiber lasers,dissipative soliton resonance,pulse shaping
更新于2025-09-23 15:21:01
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Sub-nanosecond multiple-wavelength harmonic mode-locked Tm-Ho co-doped fiber laser
摘要： We demonstrate an all-fiber sub-nanosecond passively mode-locked Tm-Ho co-doped fiber laser. With 1.1-km single-mode fiber (SMF) inserted into the cavity, the laser system can generate 183.4-kHz and 720-ps pulses based on a GaAs saturable absorber (SA). The output spectrum is presented with three wavelengths, which are at 1858.5, 1861.3, and 1864.2 nm, respectively. In addition, with the adjustment of the polarization controller and pump power, the multiple-pulse operation, such as the harmonic mode-locking operation, can also be observed. Higher order of harmonic mode locking is promising but limited by the damage threshold of the SA.
关键词： Mode-locked lasers,Ultrafast optics,Optical fiber lasers
更新于2025-09-23 15:21:01
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Mode-Locked Topological Insulator Laser Utilizing Synthetic Dimensions
摘要： We propose a system that exploits the fundamental features of topological photonics and synthetic dimensions to force many semiconductor laser resonators to synchronize, mutually lock, and under suitable modulation emit a train of transform-limited mode-locked pulses. These lasers exploit the Floquet topological edge states in a 1D array of ring resonators, which corresponds to a 2D topological system with one spatial dimension and one synthetic frequency dimension. We show that the lasing state of the multielement laser system possesses the distinct characteristics of spatial topological edge states while exhibiting topologically protected transport. The topological synthetic-space edge mode imposes a constant-phase difference between the multifrequency modes on the edges, and together with modulation of the individual elements forces the ensemble of resonators to mode lock and emit short pulses, robust to disorder in the multiresonator system. Our results offer a proof-of-concept mechanism to actively mode lock a laser diode array of many lasing elements, which is otherwise extremely difficult due to the presence of many spatial modes of the array. The topological synthetic-space concepts proposed here offer an avenue to overcome this major technological challenge and open new opportunities in laser physics.
关键词： Synthetic Dimensions,Topological Insulators,Mode-Locked Lasers,Photonics
更新于2025-09-23 15:21:01
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178 fs, 1.2 nJ pulses from an all-polarization maintaining fiber figure 8 laser based on 3 ?? 3 coupler at 1 <i>??</i> m
摘要： We report on an Yb-doped all-polarization maintaining fiber mode-locked laser based on nonlinear-amplifying-loop mirror and 3 × 3 coupler. Thanks to this coupler inducing a non-reciprocal phase-bias, the mode-locked regime can be easily achieved at the high repetition rate of 52 MHz. The cavity delivers an average power of 62 mW corresponding to a pulse energy of 1.2 nJ. We have finally demonstrated an extra-cavity nonlinear spectral stage induced by the propagation along a standard nonlinear fiber. The pulse can be then compressed down to 178 fs via a grating compressor and the corresponding peak power is then around 6 kW.
关键词： 3 × 3 coupler,mode-locked lasers,figure 8
更新于2025-09-23 15:21:01
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[OSA CLEO: Applications and Technology - San Jose, California (2015..-..)] CLEO: 2015 - Photonic generation of linearly-chirped microwave waveform with tunable center frequency and time-bandwidth product
摘要： A novel approach is presented to generate linearly-chirped microwave waveforms with tunable center frequency and expandable time-bandwidth product (TBWP). Different types of waveforms are demonstrated and the maximum measured TBWP is up to ~166.4.
关键词： Radio frequency photonics,Microwaves,Mode-locked lasers
更新于2025-09-23 15:21:01
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Effects of Power Split Ratio and Optical Delay Phase Tuning on Stabilization of Self-Mode-Locked Quantum-Dash Lasers Subject to Dual-Loop Optical Feedback
摘要： In the present work, we report a path of RF stabilization versus delay subject to self-mode-locked (SML) two-section quantum-dash (QDash) lasers emitting at ~ 1.55 μm and operating at ~ 21 GHz repetition rate using a feedback ratio controlled and optical delay phase-dependent symmetric dual-loop optical feedback. For symmetric dual-loops (equal arms of external loops), we identify the three key parameters: power-split ratio through each cavity of the external feedback loop, optical delay phase settings, and overall feedback strength back into gain section, yields jitter stabilization on integer resonance as well as on full delay range tuning. Symmetric dual-loop feedback with two optical delay phase settings (weaker cavity set to integer resonance, fine-tuning of the stronger cavity and stronger cavity set to integer resonance, fine-tuning of a weaker cavity) and four chosen combinations of feedback ratios (-19.5:-29.03 dB, -20.6:-24.3 dB, -21:-22.7 dB, -21.3:-23 dB) has been demonstrated. Based on these four chosen combinations of feedback ratios and optical delay phase settings, a path of stabilization has been identified for SML QDash lasers using symmetric dual-loop optical feedback. Our proposed dual-loop feedback schemes provide a viable path towards the stabilization of mode-locked lasers, promising for various practical applications where ultra-stable optical pulses are highly desirable.
关键词： Mode-locked lasers,Semiconductor lasers
更新于2025-09-19 17:13:59
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L-band Wavelength-Switchable Dissipative Soliton Resonance Er-doped Fiber Laser
摘要： The experiment reports a kind of L-band dissipative soliton resonance (DSR) nanosecond Er-doped fiber laser. The passive mode-locked L-band DSR pulse is achieved in a figure-eight structure by using the nonlinear-amplifying-loop-mirror (NALM). The repetition rate of pulse is 468 kHz. At the maximum pump power of 398 mW, the output power is 25 mW with a pulse energy of 45 nJ. By adjustment of polarization state in cavity, the output pulse can be switched among 4 different DSR states with central wavelength of 1572, 1585, 1590 and 1605 nm discretely, presenting different peak power and pulse width. We can determine that the adjustment of polarization state changes the loss spectra of cavity and the 4 DSR states operate in different balance points. The tunable DSR pulse duration is from 120 to 150 ns by increasing the central wavelength.
关键词： mode-locked lasers,solitons,Fiber lasers
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Robust all polarization-maintaining femtosecond fiber laser with various phase bias
摘要： We demonstrate a compact all polarization- maintaining mode-locked femtosecond fiber laser with three different non-reciprocal phase shifters. The achieved laser directly delivers 926 fs, 0.56 nJ pulses at the repetition rate of 88.3 MHz.
关键词： Femtosecond laser,Mode-locked lasers,All polarization?maintaining
更新于2025-09-16 10:30:52