We present a widely tunable all-fiber mode-locked laser based on semiconductor saturable absorber mirror (SESAM) with a linear cavity design. An easy-to-use tunable bandpass filter based on thin film cavity technology is employed to tune the wavelength. By tuning the filter and adjusting the polarization controller, mode-locked operation can be achieved over the range of 1023nm–1060nm. With the polarization controller settled, mode-locked operation can be preserved and the wavelength can be continuously tuned from 1030nm to 1053nm. At 1030nm, the laser delivers 9.6mw average output power with 15.4ps 10.96MHz pulses at fundamental mode-locked operation.

A picosecond fiber laser system based on master oscillator power amplifier (MOPA) is proposed. A passive mode-locked fiber laser with a semiconductor saturable absorber mirror (SESAM) which is with repetition rate of 29.87 MHz is used as the seed source. The repetition rate can be reduced to 574 kHz when a pre-amplifier system is combined with an acousto-optic modulator (AOM). The MOPA structure is based on rod-type photonic crystal fiber (PCF). The pulse with pulse width of 30 ps can be amplified based on properties of large mode field and high gain of PCF, and the spectral expanding caused by the self-phase modulation is effectively suppressed. Results show that the spectral linewidth of 5 dB is proportional to the peak-power of optical pulse of the proposed system (the beam quality factor M2 is 1.01 at the output power of 20 W). The peak-power of the picosecond pulse is 3.4 MW, which is near the diffraction limit. The picosecond pulse with the highest average output power of 21.86 W, pulse width of 11.1 ps, center wavelength of 1030.74 nm and linewidth of 1.75 nm at 5 dB can be obtained.

The wavelength-tunable rectangular mode-locking operation is demonstrated in an all-fiber laser based on semiconductor saturable absorber mirror. As the dissipative soliton resonance signature, the pulse duration varies from 580 ps to 2.1 ns as a function of the increasing pump power. Correspondingly, the maximum pulse energy is 9.11 nJ. Moreover, it is found that the wavelength tunable operation with a range of approximately 10 nm could be obtained by properly adjusting the polarization controllers. The characteristics of the rectangular pulses at different wavelengths are similar to each other. The demonstration of the wavelength tunable rectangular pulses would be beneficial to some applications for many fields such as spectroscopy and sensing research.

1-MW peak power picosecond, 574-kHz repetition rate green laser at 515-nm is generated from a frequency-doubled fiber amplifier. 12-ps pulses with 13.9-μJ energy at 515 nm are achieved with a noncritically phase-matched lithium triborate (LBO) crystal through second harmonic generation of a 1030 nm infrared source. The infrared source employs ultra-large-mode-area rod-type photonic crystal fiber (Rod-PCF) for direct picosecond amplification and delivers 20-W 11.6-ps 2.97-MW pulse train with near-diffraction-limited beam quality (M2 = 1.01).

In this Letter, a simple and passively mode-locking Yb-doped all fiber laser using a nonlinear polarization rotation technique operating under dissipative soliton (DS) or dissipative soliton resonance (DSR) conditions is proposed. Furthermore, using a combination of a bandpass filter and a Loyt filter, tunable single-wavelength or dual-wavelength operation under two different conditions is realized, respectively. The tunable single-wavelength DS laser has a 5 nm tuning range from 1029 to 1034 nm with a pulse width of 110 ps. The tunable single-wavelength DSR operation laser has a range of 4 nm. In-depth research on the mechanism of the conversion between DS and DSR is carried out. Particularly, under dual-wavelength DSR operation, the obtained step-like pulses consist of two rectangular pulses with different energies. This work could help give a deeper insight into normal dispersion pulses.

We report on the amplification of high-average-power and high-efficiency picosecond pulses in a self-made very-large-mode-area Yb-doped photonic crystal fiber (PCF). The PCF with a core diameter of 105 μm and a core numerical aperture of 0.05 is prepared by the sol-gel method combined with the powder sintering technique. The fiber amplification system produces the highest average power of 255 W at a 10 MHz repetition rate with a 21 ps pulse duration corresponding to a peak power of 1.2 MW. This result exemplifies the high-average-power and high-peak-power potential of this specifically designed fiber.

High-peak-power ultrashort pulse lasers are currently in demand for laser micromachining. It is an effective technique to use ultra-large-mode-field fibers to amplify the power of ultrashort laser pulses, for realizing ultrashort output laser pulses with high beam quality and high peak power. Based on a 1030 nm mode-locked tunable fiber laser, multi-stages of all-fiber preamplifiers and ultra-large-mode-field rod-type photonic crystal fiber (PCF), the output properties of rod-PCF amplifiers are demonstrated. The amplifier delivers near-diffraction-limit 30 ps pulses with maximum peak power of 2.94 MW.

The wavelength-tunable and switchable narrow bandwidth mode-locking operation is demonstrated in an all fiber laser based on semiconductor-saturable absorber mirror（SESAM）.Two narrow-band fiber Bragg gratings centered at 1029.9 nm and 1032 nm respectively with a polarization controller inserted between them are used to realize the wavelength switchable between 1029.9nm and 1032 nm.The laser delivers different pulse widths of 7.5ps for 1030 nm and 20 ps for 1032 nm.The maximum output power for both could reach ~6.5mW at single pulse operation.The output wavelength could be tuned to about 0.9nm intervals ranging from 1030.2nm to 1031.1 nm and from 1032.15 nm to 1033.7nm with the temperature change of the fiber Bragg grating,respectively.

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text Z. Wang, S. Du, J. He, Z. Wang, X. Li, and J. Zhou, "489nm Laser Generation by Frequency Doubling of Linearly-Polarized Q-Switched Rod-type PCF Laser," in Advanced Solid State Lasers, OSA Technical Digest (online) (Optica Publishing Group, 2014), paper AM5A.15. Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

A typing error in our manuscript is reported and corrected. (C) 2014 Optical Society of America

We report the generation of tunable multi-wavelength dissipative solitons. Based on an in-line birefringence fiber filter, not only single-, dual-, triple-wavelength mode-locking is achieved, wavelength tuning for single-, dual- and triple-wavelength mode-locking was realized.

A linearly-polarized, high peak power, short-pulse, Q-switching Yb-doped large-mode-area photonic crystal fiber (PCF) oscillator with three-level system operation is demonstrated. By optimizing cavity parameters and adopting linear polarization component, the laser can easily obtain linearly-polarized output over 2 W at 978 nm with polarization extinction ratio (PER) up to 43 dB without any additional wavelength filter. Less than 50 ns stable output pulses are achieved within repetition range of 10 kHz-200 kHz and short pulse of 9 ns pulse duration, 130 kW peak power at 10 kHz can be reached. The characteristics and the key issues of the laser, such as interpulse ASE, spectrum ASE around 1030 nm, are with detailed discussion in the paper.

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text J. He, S. Du, Z. Wang, Z. Wang, J. Zhou, and Q. Lou, "5 MHz High-Repetition-Rate Acousto-optic Q-Switched photonic crystal fiber laser operating at 978 nm," in Advanced Solid-State Lasers Congress, G. Huber and P. Moulton, eds., OSA Technical Digest (online) (Optica Publishing Group, 2013), paper ATu3A.06. Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

We report a high-peak-power, single-polarized master oscillator power amplification system employing polarization- maintaining Yb-doped rod-type photonic crystal fiber. The MOPA system comprises of a Q-switched microchip laser generating ~630ps pulses at 8.6 kHz repetition-rate and two amplification stages employing double cladding fiber and rod-type PCF respectively. The MOPA system obtains narrow spectral bandwidth, single-polarized pulses of 9W maximum output average power, corresponding to peak power of 1.7MW.

A linearly polarized Q-switching large-mode-area photonic crystal fiber laser at 978 nm is demonstrated. Short pulse of 14 ns duration is achieved with 36 dB polarization extinction ratio at 10 kHz repetition rate and 2 W output power.

The laser performance of a short-length Yb-doped rod-type photonic crystal fiber (PCF) laser is studied experimentally both in the three-level scheme and quasi-four-level scheme in this contribution. In the free oscillation mode, the rod-type PCF laser produce 13.6 W output power on the quasi-four-level system with center wavelength of 1030 nm. The laser operating on the three-level system is obtained with the introduction of specialized feedback around the 976 nm radiation. Up to 7 W output power is generated with wavelength centered in 978 nm.

以被动调Q的小型Nd···YAG/Cr4+···YAG激光器为种子光源,以后向抽运的掺镱双包层光纤为功率放大介质,经过一级光纤功率放大,获得了平均功率5.5W,重复频率9kHz的激光输出,脉冲宽度为575ps,峰值功率达到1MW。采用非临界相位匹配的LBO晶体,对该亚纳秒脉宽光纤放大器进行了单通倍频实验研究。当晶体温度为150.5℃、基频光功率为2.7W时,获得了平均功率1.3W、峰值功率250kW的倍频绿光输出,倍频转换效率为48%。

Core-diameter adjustment, in analogy to doping management, is proposed in this letter for balancing thermal load and nonlinear effects. In this scheme, the core-to-cladding ratio increases with increasing core diameter along the direction of signal and pump propagation. An all-fiber-integrated Yb-doped master oscillator power amplification (MOPA) is successfully demonstrated. Two segments of fiber with different core diameters but same inner-cladding diameters and doping levels are spliced together and used as gain fibers in the last stage. A maximum average output power of 200 W at an overall slope efficiency of 71% is achieved from the MOPA with a pulse energy of 2 mJ and peak power as high as 80 kW.

以被动调Q的固体薄片激光器作为种子光源,以中心波长976nm的半导体激光器为抽运源,通过端面抽运耦合,搭建了窄脉宽双包层掺镱光纤放大器。实验研究了前向、后向端面抽运方式对窄脉宽双包层掺镱光纤放大器的输出平均功率、激光光谱、脉冲宽度等特性的影响,并进行分析讨论。结果表明,采用后向抽运方式,窄脉宽双包层掺镱光纤放大器,获得了平均功率为9.3W的放大激光输出,重复频率为10kHz,脉冲宽度为450ps,峰值功率大于2MW。

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text S. Du, J. He, Z. Wang, W. Wu, Q. Lou, J. Zhou, and Y. Wei, "Millijoule-class Pulse Energy, High Peak Power Q-switching Large-Mode-Area Photonic Crystal Fiber Laser at 978nm," in International Photonics and Optoelectronics Meetings, OSA Technical Digest (online) (Optica Publishing Group, 2012), paper MTh5A.5. Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article