共查询到20条相似文献,搜索用时 15 毫秒
1.
We exploit the large anomalous dispersion in the waist of a fiber taper to offset the intracavity normal chromatic dispersion of an Yb-doped fiber laser. The fiber taper provides sufficient anomalous dispersion to ensure soliton operation of the mode-locked laser. With the taper removed from the cavity, the laser operates in a net normal dispersion regime. 相似文献
2.
We reported a wavelength-flexible all-polarization-maintaining self-sweeping fiber laser based on the intracavity loss tuning brought by the bent optical fiber. The bidirectional cavity structure achieved the self-sweeping effect due to the appearance of the dynamic grating in the active fiber with the spatial hole burning effect. Under this, a section of fiber was bent into a circle for adjusting the loss of the cavity. With a descending diameter of bent fiber circle, the sweeping range moves to the shorter wavelength and covers a wide range from 1055.6 to 1034.6 nm eventually. Both the initial wavelength of self-sweeping regime and the threshold of the fiber laser show exponential correlation with the diameter of the circular fiber. Our work provides a compact and low-cost way to achieve the broad wavelength-flexible self-sweeping operation. 相似文献
3.
设计并搭建了一种支持百纳焦耳量级的单脉冲能量输出的锁模光纤激光器.激光器基于σ型腔结构,采用掺Yb偏振型大模场面积光子晶体光纤作为增益介质,利用半导体可饱和吸收镜实现自启动锁模.激光器内没有色散补偿机理,使其工作在全正色散锁模状态.通过在谐振腔内引入多通长腔使激光器的重复频率降低至11.1 MHz,直接获得了平均功率为1.08 W,单脉冲能量为 97 nJ,脉冲宽度为4.17 ps的稳定锁模脉冲输出,经腔外色散补偿,脉冲宽度压缩至740 fs. 相似文献
4.
Vanholsbeeck F Coen S Emplit P Martinelli C Leplingard F Sylvestre T 《Optics letters》2004,29(23):2719-2721
We present a new numerical model of cascaded Raman fiber lasers that takes into account the chromatic dispersion of the fiber and includes the full spectrum of the intracavity field. This model explains and describes remarkably well a new operating regime found experimentally and reveals that chromatic dispersion is truly a new degree of freedom in the design of cascaded Raman lasers. 相似文献
5.
A continuous wavelength-swept fiber ring laser with a lithium niobate waveguide electro-optic polarization controller in an intracavity fiber Sagnac loop is experimentally demonstrated. Composite fiber Sagnac loop filters are cascaded to demonstrate discrete wavelength switching of a single-wavelength fiber ring laser. Stable single-longitudinal-mode operation is achieved by use of a Sagnac loop saturable-absorber filter. 相似文献
6.
By the use of installed fibers inside the city we demonstrated a 48.8 km ultralong Erbium-doped fiber laser in modelocking
regime with repetition rate varying from 1–10 GHz. The shortest pulse duration of 42 ps at 2.5 GHz was obtained by optimization
of intracavity dispersion. 相似文献
7.
Effects of an intracavity phase step on the spectral and spatial characteristics of pulsed dye laser radiation are studied. In the broadband operation regime of the dye laser, the lasing spectrum was strongly, periodically modulated. In the narrowband regime, periodic alteration between TEM00 and TEM01-like beam profiles is observed on tuning the laser wavelength. Two different spectral periods of these effects are recognized. The shorter period corresponds to double passage and the longer one to apparent single passage of intracavity light through the phase step on a cavity round trip. Depending on the position of the phase step along the laser cavity, single-passage period, double-passage period, or a superposition of both periods appeared in the broadband emission spectrum and in the beam profile alteration sequence. These observations demonstrate several possibilities for the control of spectral, spatial, and phase characteristics of laser beams by simple intracavity phase elements. 相似文献
8.
Jiang-Li Dong Zhi-Chao Luo Ai-Ping Luo Hui-Yi Wang Wen-Jun Cao Lu-Yan Wang 《Optics Communications》2011,284(24):5719-5722
We demonstrate a tunable and switchable dual-wavelength passively mode-locked fiber ring laser in the anomalous dispersion regime that generates high-energy pulses at a sub-100 kHz repetition rate. The nonlinear polarization rotation (NPR) technique is employed in this configuration to allow for passively mode-locked operation. By exploiting the intensity-dependent loss caused by NPR, the mode competition could be efficiently alleviated. Moreover, taking advantage of the intrinsic spectral filter induced by the intracavity birefringence, the dual-wavelength separations as well as the wavelength lasing locations could be flexibly tuned by properly rotating the polarization controller. With a repetition rate of 85.8 kHz, the laser delivers the single pulse energy of 198 nJ at a pump power of 250 mW. The combination of high per-pulse energy and flexible tunability in this fiber laser is useful for practical applications. 相似文献
9.
Wang L. Y. Xu W. C. Luo Z. C. Cao W. J. Luo A. P. Dong J. L. Wang H. Y. 《Laser Physics》2011,21(10):1808-1812
We experimentally demonstrate a passively Q-switched mode-locking (QML) operation in an Erbium-doped fiber ring laser with
net normal dispersion by using nonlinear polarization rotation technique. A 2 m long section of dispersion compensating fiber
(DCF) with extra large positive dispersion was inserted into the cavity to ensure the fiber laser working in the region of
net positive dispersion. By carefully adjusting the polarization controller, both uniform dissipative mode-locking pulses
with fundamental repetition rate and QML pulse trains with tunable repetition rate from 71.58 to 98.83 kHz are achieved. It
is found that the QML operation is caused by the interaction between the polarization state of the pulse and the intracavity
polarizer. 相似文献
10.
We study solid-state laser mode locking in the self-induced transparency regime of an intracavity absorber. Depending on the absorber dephasing, pulse energy, and resonator dispersion, we find stable coherent 2pi -pulse operation, pulse splitting, oscillatory pulse shapes, and smooth transition to incoherent saturable-absorber mode locking. 相似文献
11.
Sims RA Roth ZA Willis CC Kadwani P McComb TS Shah L Sudesh V Poutous M Johnson EG Richardson M 《Optics letters》2011,36(5):737-739
We used guided-mode resonance filters (GMRFs), fabricated using thin-film deposition and chemical etching, as intracavity feedback elements to stabilize and narrow the output spectrum in thulium-doped fiber oscillators operating in the 2?μm wavelength regime, producing linewidths of <700?pm up to 10?W power levels. A Tm fiber-based amplified spontaneous emission source was used to characterize the reflective properties of the GMRFs. Linewidths of 500?pm and a 7.3?dB reduction in transmission were measured on resonances. 相似文献
12.
An ultrafast thulium-doped fiber laser with stretched-pulse operation has been realized and investigated. The passively mode-locked oscillator emitted 119 fs pulses at a peak wavelength of 1912 nm. A normal-dispersion fiber with a high numerical aperture and small core was used for intracavity dispersion management and external compression. Numerical simulations were performed and are in good agreement with the experimental results. 相似文献
13.
Passive phase locking of an array of four fiber amplifiers by an all-optical feedback loop 总被引:2,自引:0,他引:2
We report the passive phase locking of an array of four fiber amplifiers in a unidirectional ring cavity. The feedback loop consists of a single-mode fiber that filters intracavity the far-field pattern of the four emitted beams. The pointing of the laser output can be managed by the intracavity filtering. 相似文献
14.
We experimentally explored the influence of passive harmonic mode locking on the temporal and spectral features of a ytterbium-doped fiber laser. Similar dependences of free-running linewidth of the laser carrier-envelope offset frequency (f0) on the intracavity net dispersion were observed for the fundamental-, second-, and third-order mode-locking states. Due to the reduction of nonlinear effects and supermode phase locking that balanced the third-order dispersion in the fiber cavity, the third-order harmonic mode-locking exhibited the narrowest free-running f0linewidth of ~120 kHz in the near-zero net dispersion regime. 相似文献
15.
构建了基于损耗非对称非线性光学环镜的8字腔掺铒光纤锁模激光器,并讨论了腔内滤波带宽对腔内脉冲演化和激光器输出特性的影响.在非线性光学环镜中引入双向输出耦合器,耦合器和传输光纤位置的不对称产生非互易性,实现锁模运转.利用自制的可调谐滤波器实验研究了滤波带宽对激光器的影响.当滤波带宽为2.1 nm时,腔内脉冲的演化过程受滤波和孤子效应的共同作用,激光器顺时针和逆时针输出脉冲半高全宽分别为583.7fs和2.94 ps.随着滤波带宽增大,滤波的作用逐渐减弱,激光器两路输出脉冲参数逐渐接近,并接近傅里叶变换极限脉冲.当滤波带宽较大时,腔内脉冲的演化过程受增益谱和孤子效应的共同作用,激光器顺时针和逆时针输出脉冲均为变换极限脉冲,半高全宽约为440 fs.通过调节滤波器中心波长实现了对激光器输出脉冲光谱的连续调谐,调节范围大于30 nm. 相似文献
16.
Intense lensless intracavity focusing in a saturable absorber Q-switched all-fiber laser resonator by use of loss arrangement and mode-field-area mismatch between the fibers is investigated for the first time. The intracavity power distribution was related to the locations and values of the cavity losses as the saturable absorption loss, the reflection loss of the output coupler, and the splicing loss between the gain fiber and the absorber fiber. With a mode-field-area mismatch and a reduced splicing loss with the gain fiber, a power density in the absorber fiber was achieved that was 11.9 times higher than that in the gain fiber. 相似文献
17.
基于单根10 m大模场面积保偏光子晶体光纤, 搭建了带有色散图的放大自相似振荡器; 通过仔细调节腔内色散量的大小以及位于色散补偿端的端镜前的狭缝位置和大小, 实现了稳定的锁模运转, 获得了抛物线形脉冲输出. 输出脉冲的重复频率为8.6 MHz, 脉冲宽度为6.2 ps, 光谱宽度为3.84 nm, 平均功率820 mW, 对应单脉冲能量95 nJ. 这是第一次在自相似振荡器中直接获得重复频率在10 MHz 以下的脉冲输出, 95 nJ也是目前自相似振荡器直接输出的最高脉冲能量. 通过数值模拟证实了在第一个光栅的零级反射处和狭缝滤波后可以分别实现抛物线型脉冲和高斯脉冲的两种锁模脉冲输出. 相似文献
18.
We investigate the dynamics of an erbium-doped fiber ring laser that is equipped with an intracavity hollow core photonic crystal fiber gas cell. The cell is filled with acetylene as a saturable absorber. We observe cw operation at low pressures, Q switching at intermediate pressure levels, and mode locking at high pressures applied. Moreover, we show that the transition from the cw to the pulsed mode may be exploited for sensitive gas detection. 相似文献
19.
J. -H. Han 《Laser Physics》2011,21(4):700-703
Investigation has been performed for the characteristics of the fiber ring laser incorporating an intracavity unpumped Er-doped
fiber Sagnac loop for narrow linewidth continuous wave (CW) and gain-switched pulsed operation. The gain-switched pulse has
duty cycle of 4.4% with more than 113 mW in peak power at the reflective optical filter output and the laser was stable both
in output power and the peak wavelength. 相似文献
20.
Zhen-Bin Lin Ai-Ping Luo Shi-Ke Wang Hui-Yi Wang Wen-Jun Cao Zhi-Chao Luo Wen-Cheng Xu 《Optics & Laser Technology》2012,44(7):2260-2264
The generation of dual-wavelength domain-wall rectangular-shape pulses in a highly nonlinear fiber (HNLF)-based fiber ring laser is experimentally demonstrated. The dual-wavelength lasing operation is realized by employing the intracavity birefringence-induced spectral filtering effect. An 85 m long HNLF is introduced into the fiber ring laser to enhance the nonlinear effect, which is favorable for the cross coupling between the two lasing beams. Experimentally, it was found that the interval of two domain walls in the time domain could be adjusted by simply tuning the linear cavity phase delay, which results in the achievement of different output pulse shapes. By properly rotating the polarization controller (PC), the dual-wavelength rectangular-shape pulses could be efficiently obtained. The proposed fiber laser provides a simple and efficient way to generate rectangular-shape pulse. 相似文献