掺钕保偏光纤激光器的研究

对掺钕光纤激光器输出功率沿光纤的分布以及不同光纤长度下抽运功率和输出功率沿光纤的分布进行了数值模拟.以808nm半导体激光器为抽运源，掺钕双包层保偏光纤为增益介质，对保偏光纤激光器进行了探索性的实验研究.分别就光纤不同弯曲形状和弯曲半径对激光器输出功率指标和偏振特性的影响进行了研究，实验中发现在1060nm和1092nm处有两个峰值.在波长1060nm处得到了7.35W的连续偏振激光输出，斜率效率为58.3％. 关键词： 激光技术 光纤激光器 掺钕保偏光纤 偏振     

High stable single-polarization tunable fiber laser based on Opto-DMD processor and polarization-maintaining fiber devices

A high stable wavelength-tunable fiber laser is experimentally demonstrated by using a digital-micromirror-device (DMD) processor and a polarization-maintaining erbium-doped fiber amplifier (EDFA).The electronic-addressed DMD processor is able to select and couple a waveband from of the polarization-maintaining EDFA back into the fiber ring to generate a narrow line-width laser output. The tunable fiber laser shows a line-width of 0.02 nm, a tuning step of 0.08 nm over the c-band and a side mode suppression ratio (SMSR) greater than 50 dB. The output power uniformity of 0.01 mW is achieved by using the automatic power control (APC) system under room temperature. The center wavelength fluctuation during 1 h is below 0.01 nm.     

间隔可调多波长光纤激光器的实验研究

半导体光放大器(SOA)的非均匀加宽特性对产生多波长激光非常有利。本文对两段式立奥-萨尼亚克(Lyot-Sagnac)滤波器进行了详细的理论分析,实现了一种基于半导体光放大器的新型多波长光纤激光器。它利用立奥-萨尼亚克滤波器的波长选择性,在室温下得到了约18个具有30 dB信噪比的多波长激光输出。波长范围1556~1577 nm。通过调节立奥-萨尼亚克环内的偏振控制器,多波长激光的波长间隔可在两种国际电信联盟(ITU)标准波长间隔(0.4 nm和0.8 nm)间选择。这种构型的光纤激光器具有稳定性好、波长间隔可控、信噪比高等优点。     

基于两滤波器级联和饱和吸收体的单纵模双波长光纤激光器

提出和证实了一种光纤环形激光器. 将一个带通滤波器与一个带阻滤波器级联,用一段保偏掺铒光纤作为饱和吸收体,得到了一种单纵模双波长光纤激光器. 结果表明,该激光器波长间隔为0.4 nm,边模抑制比大于49 dB.如果将两个波长进行差拍,该激光器有潜力得到49.85 GHz的微波信号.     

Erbium-ytterbium co-doped multi-wavelength double-clad fiber laser around 1612 nm

We report an erbium-ytterbium (Er/Yb) co-doped multi-wavelength laser operation around 1612 nm. The fiber laser was constructed in a figure-of-eight configuration and using a piece of polarization-maintaining (PM) Er/Yb double clad fiber as the gain medium. The oscillation laser lines around 1612 nm could be controlled by carefully adjusting the polarization controllers in the cavity, which might result in single line, dual line or triple line fiber laser operation. The line space was measured about 3.3 nm (±0.2 nm) which was believed to be strongly dependent on the length of the PM Er/Yb co-doped double-clad fiber.     

Microwave generation using an all polarization-maintaining linear cavity dual-wavelength fiber laser with tunable wavelength spacing

A stable dual-wavelength erbium-doped fiber laser with a linear cavity is formed by a polarization-maintaining uniform fiber Bragg grating (PM-FBG) and a polarization-maintaining linearly chirped fiber Bragg grating (PM-LCFBG), both of which were fabricated on a high-birefringence (Hi-Bi) fiber. Experimental results show stable dual-wavelength lasing operation with a wavelength separation of ∼0.22 nm, which can be tuned down to as small as 0.05 nm and a large optical signal-to-noise ratio (OSNR) of over 40 dB under room-temperature. Microwave signal at frequency of 9.41, 18.03 and 27.46 GHz is achieved by heterodyned the output lasing wavelengths on a photodetector.     

Switchable dual-wavelength polarization-maintaining erbium-doped fiber laser using an optical circulator as the all-reflecting mirror

A simple and effective switchable dual-wavelength polarization-maintaining erbium-doped fiber laser is proposed and demonstrated. Only using a uniform fiber Bragg grating written directly in a segment of the photosensitive and polarization-maintaining erbium-doped fiber as the wavelength selector and an optical circulator as the all-reflecting mirror, a stable simultaneous dual-wavelength oscillation is achieved with a wavelength spacing of 0.364 nm experimentally by exploiting the polarization hole burning effect at room temperature. The output can be switched between single- and dual-wavelength by adjusting the polarization controller. The 3-dB bandwidth and the side mode suppression ratio of the laser’s outputs are measured to be less than 0.01 nm and more than 50 dB. The power fluctuation and wavelength drift are measured to be less than 0.50 dB and 0.020 nm over an hour.     

基于偏振保持掺Er3+光纤的高稳定性单波长光纤激光器

研制出光敏偏振保持掺Er³⁺光纤,通过在这种光纤上紫外写入三个光纤光栅,形成对抽运激光高转化效率的谐振腔.在输出功率为23.617dBm、工作波长为976nm的激光抽运下,得到均值功率为9.20dBm、均值中心波长为1554.554nm的单波长激光输出.在室温下800min（约13.3h）的测量时间内,其输出功率的波动为±0.05dB,中心工作波长的波动为±0.0015nm. 关键词： 光纤激光器 3+光纤')" href="#">偏振保持掺Er³⁺光纤 光纤Bragg光栅     

Switchable triple-wavelength erbium-doped fiber laser using a single fiber Bragg grating in polarization-maintaining fiber

A stable and narrow wavelength spacing multiwavelength erbium-doped fiber laser is proposed and demonstrated. The laser can produce simultaneous dual- and triple-wavelength lasing oscillations with a narrow wavelength spacing of less than 0.1 nm via using a single fiber Bragg gratings written in polarization-maintaining (PM) fiber. By adjusting polarization controller, the wavelength spacing of dual-wavelength lasing oscillations can be tuned to as small as 0.032 nm. The maximum amplitude variation for every lasing wavelength is less than 0.5 dB. The room-temperature operation principle is based on the polarization hole burning and deeply saturated effect in an ordinary erbium-doped fiber ring laser (EDFRL). The laser has the advantages of simple all-fiber configuration, low cost, high stability and operating at room temperature.     

All-fiber mode-locked fiber laser

An environmentally stable mode-locked fiber laser based on nonlinear polarization rotation is experimentally demonstrated. The laser is based on a novel laser configuration that has negligible low-power steady-state reflectivity from one side and, consequently, no CW gain. The laser is self starting and the configuration is implementable as an all-fiber laser with standard polarization-maintaining fiber-pigtailed components. A pulse duration of 5.6 ps is obtained at a repetition rate of 5.96 MHz and at an average power of 8 mW. As an application of the proposed laser configuration, 213 mW of supercontinuum (600-1750 nm) was demonstrated from a fiber laser system with no sections of free-space optics.     

Multi-wavelength mode-locked Er/Yb Co-doped fiber laser with square nano-second pulse output

We report a multi-wavelength mode-locked Er/Yb codoped fiber laser with square nano-second pulse output, which is constructed with a “figure-of-eight” cavity structure. A section of polarization-maintaining Er/Yb co-doped double clad fiber was used as the gain medium and pumped by a fiber pigtailed multimode laser diode working at 975 nm via a multimode fiber combiner. Several megahertz repetition rate output pulses with peak power up to 9.2 W and pulse duration around several nanoseconds were obtained.     

Stable and spacing-adjustable multiwavelength Raman fiber laser based on mixed-cascaded phosphosilicate fiber Raman linear cavity

A novel multiwavelength Raman fiber laser based on the mixed-cascaded Stokes effects of phosphosilicate fiber is proposed and demonstrated experimentally. By using stimulated Raman scattering of both P(2)O(5) and SiO(2) along 1 km phosphosilicate fiber pumped with a 1064 nm double-clad fiber laser, the mixed-cascaded Raman linear cavity is formed by a pair of fiber Bragg gratings at 1239 nm, a polarization-maintaining fiber (PMF) Sagnac loop filter, and a conventional optical loop mirror. Up to 15-wavelength stable oscillations around 1320 nm are obtained with a wavelength spacing of 0.44 nm and power nonuniformity of less than 4 dB. By changing the length of the PMF in the Sagnac loop filter from 10 to 5.5 m, the wavelength spacing is adjustable from 0.44 to 0.8 nm. The extinction ratio of the laser is more than 30 dB. Excellent stability is also observed with a peak power fluctuation of less than 0.8 dB in 1 h.     

Single-frequency laser oscillator with watts-level output power at 1.5 microm by use of a twisted-mode technique

We report an all-fiber laser oscillator producing as much as 1.9 W of single-frequency direct output at 1.5 microm. Spatial gain hole burning in the active fiber has been eliminated by use of a twisted-mode cavity approach. The two short pieces of a polarization-maintaining fiber that were spliced to the ends of the active fiber served as ultracompact quarter-wave plates. To our knowledge, the use of such a wave plate to manipulate the polarization state of light inside a fiber laser cavity is reported here for the first time. The laser output is linearly polarized and delivered through a polarization-maintaining fiber pigtail. We believe that the output power of our laser is the highest among all single-frequency fiber laser oscillators reported to date.     

High repetition rate Tm：Ho：LuLiF master-oscillator and Tm-doped fiber power-amplifier system

A high repetition rate Tm:Ho:LuLiF master-oscillator and polarization-maintaining (PM) Tm-doped fiber power-amplifier system is presented.A 11.3-kHz,0.4-nm line width,0.89-W Tm:Ho:LuLiF seed laser is developed.Using a two-stage PM Tm-doped fiber power amplifier system,32.4-W output power is obtained with 0.4-nm line width at a central wavelength of 2058.5 nm,corresponding to 0.66-W seed laser.The laser spectrum and pulse profile are measured.     

Incorporate, switchable dual-wavelength fiber laser with Bragg gratings written in a polarization-maintaining erbium-doped fiber

A stable, incorporate and switchable dual-wavelength fiber laser with two fiber Bragg gratings written in a photosensitive and polarization-maintaining erbium-doped fiber directly, that is, without splices in the laser cavity, is proposed and demonstrated. Simultaneous dual-wavelength oscillation is achieved at room temperature with a wavelength spacing of 0.343 nm. The power fluctuation and wavelength shift of single-wavelength oscillations are measured to be less than 0.24 dB and 0.013 nm over 2 h. The wavelength switchability between single- and dual-wavelength oscillations is realized by altering the voltage upon the electrostrictive ceramic actuator.     

基于长周期光纤光栅和保偏光纤Sagnac环光谱特性的温度与应变测量研究

提出并研制了一种结构简单、成本低廉的温度与应变同时测量系统,其结构是在保偏光纤Sagnac环内接入一个长周期光纤光栅(LPFG)。利用LPFG对保偏光纤Sagnac环的透射光谱进行调制,通过监测谐振峰波长和强度的变化,发现波长随温度和保偏光纤的应变变化,强度随LPFG的应变变化,因此可以实现温度与应变的区分测量,并且可判断出应变的施加位置。实验得到该系统的温度灵敏度为0.181 81 nm·℃-1,LPFG区的应变灵敏度为0.005 283 dB·με-1,保偏光纤Sagnac环区的应变灵敏度为0.015 72 nm·με-1。实验结果表明该方案可行,并具有一定的实用性。     

基于高双折射Sagnac环的可调环形腔掺铒光纤激光器理论与实验研究

报道了一种利用偏振控制器（PC）和保偏光纤（PMF）组成的高双折射Sagnac干涉环实现选频和调谐的环形腔掺铒光纤激光器.理论模拟了PMF和PC对波长的控制作用.实验中调节PC得到了单波长、双波长和多波长激光;并验证了滤波间隔随PMF长度的变化规律.实验中得到了斜率效率20%,3 dB线宽0.016 nm,30 dB线宽0.097 nm,边模抑制比（SMSR）40 dB左右的稳定激光输出. 关键词： 光纤激光器 Sagnac干涉环 环形腔 掺铒光纤     

A stable dual-wavelength fiber laser with tunable wavelength spacing using a polarization-maintaining linear cavity

We propose and experimentally demonstrate a stable dual-wavelength erbium-doped polarization-maintaining (PM) fiber laser with tunable wavelength spacing using an all-PM linear cavity that makes use of two reflection peaks from the PM fiber Bragg grating (PM-FBG). Experimental results show stable dual lasing lines with a wavelength separation of ∼0.22 nm and a large optical signal-to-noise ratio (OSNR) of over 40 dB under room temperature. By applying axial strain to the PM-FBG, the center wavelengths of the two lasing lines can be tuned over several nanometers and the wavelength separation between the lasing lines can also be tuned to as small as 0.05 nm, which, to our knowledge, is the smallest wavelength spacing ever obtained from a stable room-temperature dual-wavelength fiber laser. The proposed laser configuration has the advantages of simple structure, low loss, stable dual-wavelength operation and a very small lasing linewidth of ∼5 kHz . PACS 42.55.Wd; 42.81.-i; 42.81.Gs     

多色脉冲激光光源研究

采用钛宝石锁模飞秒激光器作为泵浦光源,利用1.8 μm纤芯的保偏光子晶体光纤的高非线性特性产生超连续谱,通过调节泵浦光源和光子晶体光纤之间的耦合,在可见光区,获得了中心波长分别在431 nm, 497 nm, 520 nm, 575 nm的mW量级的不同颜色的激光输出,并且测量输出的脉冲序列重复频率与泵浦光的一致,具有良好的稳定性.     

High-peak-power femtosecond pulse compression with polarization-maintaining ytterbium-doped fiber amplification

We report the generation of 140 fs pulses with a peak power of up to 270 kW using a fiber pulse source based on a polarization-maintaining ytterbium-doped fiber amplifier and a semiconductor saturable absorber mirror mode-locked fiber laser seed. The seed laser pulses were amplified and chirped in the fiber amplifier and subsequently compressed in an external transmission grating pair. The use of a polarization-maintaining amplifier addresses nonlinear polarization-induced limitations to the obtainable compressed pulse duration and quality that can arise if isotropic fiber amplification is used. Numerical simulations of the system support the experimental measurements and also confirm the role of fiber dispersion in obtaining high-quality compressed pulses.