Self-starting all-fiber PM Er:laser mode locked by a biased nonlinear amplifying loop mirror

A compact all-fiber polarization-maintaining Er:laser using a nonlinear amplifying loop mirror is reported. Fundamental single-pulse mode-locking operation can always self start, with a cavity round-trip decreased from ~ 4.7 m to~ 1.7 m. When the pulse repetition rate is 121.0328 MHz, output pulse is measured to have a center wavelength/3-d B spectral bandwidth/radio frequency signal to noise ratio(SNR)/pulse width of 1571.65 nm/18.70 nm/80 d B/477 fs, respectively. Besides, three states including the exponential growth, damping state, and steady state are investigated through the build-up process both experimentally and numerically. Excellent stability of this compact Er:laser is further evaluated,demonstrating that it can be an easy-fabrication maintenance-free ultrafast candidate for the scientific area of this kind.

Generation of 47 fs Pulses from an Er:Fiber Amplifier

We demonstrate a self-starting erbium fiber oscillator-amplifier system based on the nonlinear polarization rota- tion mode-locked mechanism. The direct output pulse from the amplifier is 47fs with an average power of 1.22 W and a repetition rate of 50 MHz, corresponding to a pulse energy of 24 nJ. The full width at half-maximum of the spectrum of the output pulses is approximately 93nm at a central wavelength of 1572nm so that the transform- limited pulse duration is as short as 39 fs. Due to the imperfect dispersion compensation, we compress the pulses to 47fs in this experiment.

Radiation-induced attenuation self-compensating effect in super-fluorescent fiber source

The compact super-fluorescent fiber source （SFS） output spectra variations at different pump currents and under different dose of gamma-ray radiation were measured and compared respectively. The radiation-induced attenuation （RIA） self-compensating effect in SFS based on photo-bleaching was found and the general mathematic model of SFS output spectra variations was made. The radiation-induced background attenuation （RIBA） at the pump wavelength was identified to be the main cause of the total output power and spectra variations and the variations can then be compensated by active control of the pump power to enhance the self-compensating effect. With closed-loop feedback control of pump current, double-pass backward （DPB） configuration and spectrum re-shaping technology, an SFS prototype was made and tested. The mean-wavelength stability of about 87.4 ppm and output power instability of less than 5% were achieved under up to 200 krad （Si） gamma-ray irradiation.

Preparation and ASE Spectrum of a Single-Mode Erbium Doped Tellurite Glass Fiber with D-type Cladding Geometry

Based on the host of tellurite glasses, the glass formation, preform manufacture, and fiber fabrication are described. The characterization of amplified spontaneous emission (ASE) from this newly fabricated single-mode Er3+-doped tellurite fibers is also presented. When pumped at 980 nm, a very broad erbium ASE around 1.53 μm was observed. The variations of ASE with fiber length and pumping power are measured and discussed. The output of 2 mW from Er3+-doped tellurite fiber ASE source was obtained under the pump power of 660 mW.

Dispersive Nonlinearity in Er-Doped Optical Fiber

Optical dispersive nonlinearities in Er-doped optical fiber are discussed and measured at the third window wavelength 1.55 μm for optical communications firstly. The experimental method, which is developed by us, is based on dynamic scanning for fixed-point-interference (DSFPI) of two fiber beams. The real part and complex value of the third-order susceptibility at the wavelength are also obtained from the measured Kerr coefficient and nonlinear-absorption coefficient reported elsewhere.

Optical Fiber Grating Bistability

It is proposed that a segment of Er doped fiber with a couple of fiber gratings on the ends may be used as a novel optical bistability device with low power and high speed. Operation and bistability threshold of device are analysed in accordance with the distributed feedback couple mode theory and the nonlinear characteristic of Er doped fiber. It is shown that a nanoseconds microwatts bistable operation of a centimeter device is realizable under nowaday technological condition.

1.55 μm Wavelength Operation of E_r^(3+) -Doped Optical Fiber Bistability

An all optical all fiber optical bistability operation has been realized in an all fiber cavity consisted with Er doped fiber and optical fiber loop mirrors. The experimental bistability threshold is consistent with the theory.

Absorptive Nonlinearity in Er-Doped Optical Fiber

Optical absorptive nonlinearity in Er doped optical fiber has been discussed and measured at the window wavelength 1.55 μm for optical communications firstly. It is proposed that the mechanism of this absorptive nonlinearity is the induced absorption. The first order nonlinear absorptive coefficient and the imaginary part and the complex value of the third order susceptibility at that wavelength are obtained from the measured absorptive nonlinearity.

Bismuth and Erbium Co-doped Optical Fiber for a White Light Fiber Source

We demonstrate a white light fiber source based on Bismuth and Erbium co-doped fiber and a single 830nm laser diode pump. The light spectral intensity from 1100 to 1570nm is over -45dBm, which provide ~40dB dynamic range for an OSA based spectral measurement.

3μm波段Er^(3+)∶ZBLAN光纤激光器研究进展及展望

3µm激光处于分子指纹区,在医疗外科、气体检测、军事应用等领域都有重要的应用价值。Er^(3+)∶ZBLAN光纤激光器具有效率高、可集成的优点,是3µm激光的主要输出方式。本文从铒离子跃迁产生3µm激光出发,围绕Er^(3+)∶ZBLAN光纤激光器,介绍了3µm激光产生的结构原理及能级系统,总结了实现该波段高功率连续输出和脉冲输出的技术方案和研究进展,重点介绍了基于不同材料可饱和吸收体的调Q和锁模激光器实验研究,并对目前实现3µm波段高功率输出需要解决的问题进行了分析,最后对Er^(3+)∶ZBLAN激光器的发展方向进行了展望。

E_r^3+-doped Fiber Optical Bistability by Ar^+-laser

s:Under The nonlinear optics condition the all-fiber optical bistability operation has been realized in an all-fiber resonator consisted of Er-dope fiber and optical fiber couplers.The experimental bistability threshold is consistent with the theory.

Nonlinear Optical Fiber Resonator:Optical Fiber Bistability

The linear and nonlinear charecteristics of verious optical riber loop resonators have been processed uniformly using transmission matrix method. It is pointed that in nonlinear operation condition each of those optical fiber loop resonators may be used to make an all-optical fiber bistabillty device.The configuration,charecterictics and threshold of verious Er-doped fiber loop bistability devices have been calculated,analysised, and compared, and the design principle of those devices has been given.

2.856 GHz microwave signal extraction from mode-locked Erfiber lasers with sub-100 femtosecond timing jitter

A balanced optical microwave phase detector(BOMPD) based on a 3 × 3 coupler is presented. This system was developed to extract ultra-low-jitter microwave signals from optical pulse trains emitted by mode-locked Er-fiber lasers, and synchronized microwave and laser systems. We demonstrate that the BOMPD achieves a precision of synchronization of less than 100 femtosecond of timing jitter. The experimental setup can be applied to the soft X-ray free-electron laser located on the campus of the Shanghai synchrotron radiation facility. A microwave signal with a 2.856 GHz frequency is extracted from a238 MHz mode-locked Er-laser, with an absolute timing jitter of 34 fs in the 10 Hz–10 MHz frequency offset range.In addition, the microwave and 238 MHz optical pulse signals are synchronized with a relative timing jitter of16 fs at the same frequency offset range.

Chirp Extraction of Self-Similar Pulses in a Passively Mode-Locked Er-doped Fiber Laser

In this paper, we adopt cloud computing in a specific scientific computing field for its virtualization, distribution and dynamic extendibility as follows: We obtain high-energy parabolic self-similar pulses by numerical simulation using our non-distributed passively mode-locked Er-doped fiber laser model. For researching characteristics of these wave-breaking-free self-similar pulses, chirp of them must be extracted. We propose several time-frequency analysis methods adopted in chirp extraction of ultra-short optical pulses for the first time and discuss the advantages and disadvantages of them in this particular application.

Er^(3+)/Yb^(3+)共掺光纤激光器中能量上转换的抑制

通过对掺Er3+和Er3+/Yb3+共掺光纤激光器的输出功率进行数值模拟发现 :高浓度的Er3+/Yb3+共掺光纤激光器的最大量子转换效率比同等浓度下的掺Er3+光纤激光器的最大量子转换效率高出一倍。说明由于Yb3+的加入 ,Er3+/Yb3+共掺光纤激光器有效地抑制了能量上转换 。

双包层Er^(3+)/Yb^(3+)共掺光纤激光器的实验研究

通过采用长度为 2m、入纤功率为 1W的双包层Er3 + /Yb3 + 共掺光纤作为增益介质所进行的双包层Er3 + /Yb3 + 共掺光纤激光器的实验 ,得到了波长为 15 6 3.5 96nm、功率为 2 4

双包层Er^(3+)/Yb^(3+)共掺光纤激光器稳态特性的分析

对 98 0nm泵浦光泵浦双包层Er3 + /Yb3 + 共掺光纤激光器进行了数值模拟 ,分析了泵浦光与激光在双包层Er3 + /Yb3 + 共掺光纤中的分布情况、输出功率与泵浦功率的关系、光纤长度与腔镜反射率对输出激光功率的影响 ,计算的最大斜效率为 5 6 .3%,接近于理论计算值的极限。

环形掺Er^(3+)光纤激光器输出特性分析与实验研究

理论分析了掺Er3+光纤环形腔激光器的输出特性,获得了稳态条件下激光器输出功率、阈值泵浦功率和斜率效率的解析表达式,分析了泵浦光波长、泵浦功率、Er3+光纤掺杂浓度、输出端耦合器分光比等的影响,推导了在特定输出波长处获得最大输出功率所需最佳掺Er3+光纤长度的解析表达式。进行了LD泵浦掺Er3+光纤环形腔激光器的实验工作,获得了斜率效率10%以上的激光输出。

双包层Yb／Er共掺光纤放大器的数值模拟

为优化光纤放大器结构,对980 nm抽运的双包层Yb/Er共掺光纤放大器进行了数值模拟,分析了不同功率下信号光的增益,计算了稳态情况下光纤中的反转粒子数、抽运光功率、信号光功率沿光纤轴向的分布以及放大器的斜率效率。根据数值模拟的结果,采用10 m长的双包层Yb/Er共掺光纤建立了光纤放大器实验装置。最大光纤抽运功率为6 W,初始信号光功率为0.5 W时,获得了1.9 W的最大输出功率,斜率效率为23.4%。

掺Er^(3+)飞秒光纤放大器的特性研究

依据二能级速率方程和光传输方程 ,理论计算了Er3 + 光纤放大器中Er3 + 光纤的最佳长度Lc 以全光纤飞秒激光器输出的孤子脉冲作为种子源 ,以理论值Lc 作为实际采用的光纤长度 ,实验测量了Er3 + 光纤放大器在同向泵浦和反向泵浦下信号光的输出功率 ,得到同向泵浦的增益为2 0 .0dB ,反向泵浦的增益为 2 0 .2dB 同时测量了脉冲宽度随泵浦功率的变化 ,实验结果表明 ,随着泵浦功率的增大 ,输出光脉冲的宽度的压缩效应经历逐渐增强后逐渐减弱的过程 在同向泵浦方式下 ,可以得到更短的输出脉宽 ,其最短脉冲宽度为 2