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.

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.

Optical Switching and Digital Signal Amplification Using an Optical Fiber Grating OBD

It is proposed that an optical fiber grating bistability device may be used for an all optical switching or an all optical digital signal amplifier with low power and high speed. The principle, characteristic and paremeter are analysed, and some design ideas are given.

Optical bistability in tunable fiber laser using fiber Mach-Zehnder interferometer

In this letter, a novel mechanism of hybrid optical bistability is proposed by using nonlinear mechanism in the frequency domain. This device is based on electro-optical feedback through the fiber Bragg grating on piezoelectric transducer (PZT) to tune continuous wave (CW) fiber laser. The optical bistable characteristics for two manners of separately alternating input power and bias voltage are discussed. The smallest wavelength shift of the order of 0.001 nm needed to realize a switching process in this optical bistability device is estimated. The potential applications of this device in the optical fiber sensor technique are also discussed.

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.

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.

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.

Wavelength-switchable erbium-doped fiber ring laser employing a chirped Moiré fiber grating

A simple and cost-effective wavelength-switchable fiber ring laser based on a chirped moire fiber grating (CMFG)and an erbium-doped fiber amplifier (EDFA) is proposed,and stable wavelength Iasing oscillations at room temperature iS experimentally demonstrated.To serve as a wavelength selective element,the CMFG possesses excellent comb-like filtering characteristics including stable wavelength interval and ultra-narrow passband.and its fabrication method iS easy and flexible.The measured optical signal-to-noise ratio reaches the highest value of 50 dB and the power fluctuation of each channel output iS less than 0.5 dB within an hour.The output laser power of different channels is almost identical(difference of less than 1 dB) within the tunable range.Methods to optimize the laser performance are also discussed and the superiority of the CMFG iS experimentally demonstrated.

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.

Comparative study of fiber optic liquid level sensors based on long-period fiber gratings with dif ferent doping concentrations

The performances of two liquid level sensors based on long-period fiber gratings are studied. The long- period gratings （LPGs） have similar characteristics （length and period）, but are fabricated with two pho- tosensitive B-Ge co-doped fibers with different dopant concentrations. We investigate the temperature sensitivities of LPGs and exploit their refractive index sensitivity to implement liquid level measurement. By controlling fiber parameters, such as the dopant concentrations, the measurement sensitivity of a LPG- based fiber optic liouid level sensor can be improved.

Triple and Double Photons Absorption Process and Down-Conversion Laser Emitting Investigation of Er-Ion Doped Microsphere

We report a readily and cheap method to build taper optical fiber-Er3+ doped microsphere platform to investigate upconversion fluorescence emission and down-conversion laser oscillation with low threshold pump power. We demonstrate to dope Er3+ into silica microsphere surface by dipping a single-taper optical fiber into a certain concentration of erbium nitrate solution (Er(NO3)) , then dry it and use the electrical-arc of the optical fiber splicer to melt the tip of taper fiber to form the Er3+-doped silica microsphere due to surface tension induced. We also present a HF acid etching setup to fabricate low loss biconical optical taper fibers. We demonstrate the Er3+ doped silica microsphere triple photons and dual photons absorption process of up-conversion fluorescence emission and down-conversion laser oscillation spectra by using the optical tapered fiber to couple 976 nm/1534 nm pump light source.

Development of Bi/Er co-doped optical fibers for ultra-broadband photonic applications

Targeting the huge unused bandwidth（BW）of modem telecommunication networks,Bi/Er co-doped silica optical fibers（BEDFs）have been proposed and developed for ultra-broadband,high-gain optical amplifiers covering the 1150-1700 nm wavelength range.Ultrabroadband luminescence has been demonstrated in both BEDFs and bismuth/erbium/ytterbium co-doped optical fibers（BEYDFs）fabricated with the modified chemical vapor deposition（MCVD）and in situ doping techniques.Several novel and sophisticated techniques have been developed for the fabrication and characterization of the new active fibers.For controlling the performance of the active fibers,post-treatment processes using high temperature,γ-radiation,and laser light have been introduced.Although many fundamental scientific and technological issues and challenges still remain,several photonic applications,such as fiber sensing,fiber gratings,fiber amplification,fiber lasers,etc.,have already been demonstrated.

双包层Er^(3+)/Yb^(3+)共掺光纤激光器动态特性的分析

分析了弛豫振荡前上能级Er3+、Yb3+粒子数的变化和弛豫振荡时Er3+上能级粒子数的变化情况以及弛豫振荡时激光功率的变化规律 ,结果表明

使用FBG及更短光纤的高效Er^(3+)Yb^(3+)共掺双包层光纤放大器(英文)

提出在光纤放大器中 ,使用光纤布喇格光栅作为泵浦光反射镜 ,所需的双包层光纤可以缩短 ,同时至少保持了与没有光纤布喇格光栅作为反射镜时光纤放大器相同的性能 基于速率及传输方程 ,对使用和不使用光纤布喇格光栅的铒、镱共掺双包层光纤放大器的性能进行了数值模拟 结果表明 ,使用光纤布喇格光栅作为反射镜时光纤放大器可以获得与无光栅时相同的输出功率 ,但仅仅需要后者长度一半的光纤 ,无论是前向泵浦还是后向泵浦 对后向泵浦方式并使用光纤布喇格光栅作为反射镜 ,可获得最高的输出功率及光增益 。

飞秒被动锁模环形腔掺Er^(3+)光纤激光器

在考虑增益、损耗、群速度色散、自相位调制、快速可饱和吸收体等各种参数同时作用情况下,分析了非线性偏振旋转效应自启动锁模机理,研究了腔体参数与锁模脉冲之间的关系,并给出飞秒被动锁模环形腔掺E r3+光纤激光器实验原理。实验采用性能稳定的980 nm半导体激光器作为抽运源,高掺杂短长度掺E r3+光纤作为增益介质,利用非线性偏振旋转锁模技术,得到了稳定的飞秒自起振锁模光脉冲。抽运功率为23 mW时,激光器输出锁模脉冲中心波长1 552 nm,3 dB带宽为7.6 nm,重复频率14.0 MH z,平均输出功率0.43 mW,自起振锁模泵浦阈值功率11.5mW,并观测到了稳定的高阶锁模脉冲输出。该激光器与报道过的相同结构光纤激光器相比,自起振泵浦阈值低、脉冲能量高、稳定性好,且频谱边带幅度小。

高功率Er/Yb共掺光纤超荧光光源

为了获得高功率超荧光输出,采用6个976nm的LD,通过一个光纤束耦合器同时抽运Er/Yb共掺光纤,分别研究了单程后向结构和双程后向结构超荧光光源的输出特性。采用单程后向装置,当抽运功率为957mW时,输出功率为120.4mW,斜率效率达到17.5%。在双程后向结构的实验装置中加入4m掺Er光纤,有效地将超荧光的3dB带宽拓展到88nm。

双程前向包层抽运宽带Er^(3+)/Yb^(3+)共掺超荧光光纤光源(英文)

为了研究基于双程前向结构的宽带Er3+/Yb3+共掺双包层光纤超荧光光源,采用976nm抽运,通过优化抽运功率,研究了采用不同长度光纤时光源的输出功率、平均波长和带宽。实验结果表明,采用60 cm长的Er3+/Yb3+共掺双包层光纤时,系统达到了最佳。同时获得了9.18mW的输出功率和34nm的带宽,平均波长稳定性约7.16×10-6/mW。当输出功率减少至3.78mW时,系统获得了80nm的最大带宽。

掺Er光纤飞秒激光器中电光晶体对激光器参数的影响

由于受增益介质上能级寿命的影响,掺Er光纤光梳的梳齿线宽一般在百kHz量级.为了实现光梳梳齿线宽的压窄,一种有效的方法是在激光器中增加快速响应的电光晶体,使光纤光梳的伺服锁定带宽提高到百kHz以上,为光纤光梳的快速伺服锁定提供反馈机构.这其中,高品质的飞秒激光器是核心.基于此,本文主要研究了掺Er光纤飞秒激光器中电光晶体对激光器参数的影响.通过计算电光晶体的折射率、色散、相位延迟等参数,分析了电光晶体对激光器参数的影响,并在实验上获得了电光晶体电压对激光器重复频率和载波包络偏移频率的影响,进而通过电光晶体实现了对光纤光梳重复频率和载波包络偏移频率的锁定.通过锁定光纤飞秒激光器与窄线宽激光器的拍频信号,验证了电光晶体的引入使激光器的伺服锁定带宽提高到了236 kHz,为窄线宽飞秒光学频率梳的建立提供了技术基础.

Er-Yb共掺光纤光栅光纤激光器

提出了一种用两个完全相同的光纤光栅作谐振腔的Er-Yb共掺光纤激光器,并对其输出与温度特性进行实验研究,给出了Er-Yb共掺光纤的自发辐射谱及光纤光栅的透射谱,讨论了光纤光栅工作温度对激光器输出中心波长的影响。实验结果表明激光器的温度稳定性较好。