Tunable electroabsorption modulated laser integrated with a bent waveguide distributed-feedback laser

The fabrication of the first 1.55-/spl mu/m wavelength tunable electroabsorption modulated laser integrated with a bent waveguide distributed-feedback laser is reported. A low-threshold and stable single-mode operation is obtained when the devices were uniformly pumped. A single-mode output power close to 10 mW from a single-mode fiber (40 mW in free space) is obtained with a 0 V bias to the modulator and an extinction ratio of up to 15 dB at 2.5 V. This single mode stability is due to the continuously distributed phase shift implemented in the structure. With a nonuniform injection, it was possible to select one particular mode out of the three neighboring modes inside the broad-reflection band of the reflector. A tuning range of 3.5 mm was obtained while maintaining an output power of more than 2 dBm from each mode.     

Tunable low-reflection waveguide termination

A low-reflection sliding load in WG11A is described. The load is constructed from sections of lossless and lossy dielectric which completely fill the waveguide cross-section and which can be moved longitudinally in the guide with respect to each other. The reflection coefficient can be set to zero to within 0.0002.     

Gain characteristics of 6 cm-long Er-doped bismuthate waveguide

Er-doped multicomponent bismuthate channel waveguides have been fabricated. Dependence of emission lifetime of Er/sup 3+/ ions on the concentration of Er/sup 3+/ ions is investigated and compared with the other silicate materials. The loss and gain characteristics of the channel waveguide are reported.     

基于掺Er光纤放大器的可调谐微波光子滤波器

提出了一种基于掺Er光纤放大器(EDFA)的光纤环结构可调谐微波光子滤波器.在光纤环结构中引入掺Er光纤(EDF),通过增加泵浦功率提供增益来补偿器件损耗,从而增加了信号的有效采样数,大大改善了滤波器的性能.在泵浦功率为42.7 mW时,实现了通带3 dB带宽为0.15 MHz、Q值为100和抑制比为20 dB的微波光子滤波器.进一步通过在光纤环结构中引入可调光纤延迟线(TODL),实现了可调谐微波滤波器.     

Bidirectional single-mode Er-doped fiber-ring laser

A Faraday rotator is used in a laser cavity to eliminate spatial hole burning in a bidirectional Er-doped fiber-ring laser. A stable operation is achieved in single longitudinal mode with comparable intensities for both clockwise and counter-clockwise directions. A beat signal between the clockwise and the counter-clockwise laser outputs of 40 dB above noise and of about 30% fringe visibility is observed.     

Bidirectional single-mode Er-doped fiber ring laser

Rare Er-doped fiber lasers have been studied for fibe sensor applications with the advantage of frequency readou [1,2]. Due to this advantage, gyroscope application for a bidi rectional Er-doped fiber-ring laser was also demonstrated They also have high s…     

Tunable narrow-band thin-film waveguide grating filters

A tunable, narrow-band thin-film filter consisting of two uniform grating filter sections separated by a phase-shift section is proposed, and the theoretically predicted performance of these new components is verified experimentally. A straightforward method of calculating the reflection spectrum of these structures is also presented; the technique is particularly well suited to accounting for the effects of parasitics in practical structures. Finally, a qualitative model useful for intuitive analysis of these filters and their spectra is described.     

基于环型腔掺Er光纤激光器的FBG传感系统

提出并实验了一种基于可调谐环型腔掺Er光纤激光器的光纤光栅（FBG）传感解调系统。传感FBG与受一维调节器调节控制的匹配FBG共同构成环型腔掺Er光纤激光器的窄带滤波器。一维调节器与步进电机相连,步进电机由PC通过可编程逻辑控制器（PLC）进行控制,一维调节器通过调节匹配FBG的周期以匹配传感FBG的周期从而滤除激光的输出,由激光的输出特性来判断2个FBG周期的匹配性并完成对传感FBG周期的测量。调节器控制系统、激光信号检测电路与数据处理模块共同完成传感信号的解调。实验测得,在4．04nm范围内,系统的波长探测精度为0．02nm。     

Tunable fibre-extended-cavity laser

A tunable fibre-extended-cavity laser is demonstrated consisting of an InGaAsP superluminescent diode, a single-mode fibre with an integral microlens and a variable-period diffraction grating coupled to the fibre. A tuning range of 450 ? has been observed, limited by the gain spectrum of the gain medium.     

一种可调谐掺铒光纤激光器的研究

文章基于掺铒光纤在1 550 nm波段的增益特性,利用光纤光栅作为调谐装置,设计了可调谐光纤光栅激光器的简单结构,通过改变光纤光栅的温度对光纤激光嚣的波长进行了调谐.更重要的是实验分析了不同掺铒光纤长度对激光输出功率的影响,在温度为25℃时,实验中分别取10、20和30 m 3种不同光纤长度进行了测试,结果表明,不同长度的掺铒光纤,其阀值不同.     

基于法布里-珀罗腔游标式级联可调谐滤波器的研究

设计了一种基于LiNbo3衬底的法布里——珀罗腔游标式级联电光可调谐滤波器，利用多光束干涉原理对单个滤波器的电压频率响应特性进行了分析模拟，对由两个滤波器级联实现的多个波长的动态滤波进行了分析，结果的性能满足波分复用信号的滤波要求。     

Glass waveguide laser

A channel waveguide fabricated in a Nd³⁺-doped laser glass by the ion exchange method is discussed. The device was end-fire pumped by a diode-laser operating at 802 nm. Continuous-wave (CW) lasing was observed at 1054 nm, and maximum output power was higher than 150 mW. The large output power was achieved by increasing the radius of the waveguide     

Tunable Raman fibre-optic laser

Continuous tuning of the oscillation frequency of a continuous-wave Raman fibre-optic laser has been demonstrated. The device operates over a 3 nm band in the visible range and exhibits low threshold and high conversion efficiency.     

Tunable thulium-doped all-fiber laser

We demonstrate a tunable thulium-doped fiber ring laser wherein a single fused coupler acts simultaneously as the wavelength-division multiplexing for pump radiation, a lasing wavelength selective element, and output mirror. Temperature tuning of up to 2 nm/°C over a range of 40 nm and polarization tuning of over 100 nm within the spectral range from 1810 to 1930 nm have been obtained     

Tunable dual-wavelength fiber laser

A narrow-linewidth, tunable, dual-wavelength fiber laser operating at room temperature with each lasing wavelength in single-longitudinal-mode operation is demonstrated. A commercially available tunable fiber Bragg grating was used to tune one of the lasing lines. An unpumped elliptical-core erbium-doped fiber was used as a saturable absorber to suppress mode hopping. Wavelength switching was achieved using a polarization controller. The linewidth (FWHM, full width at half maximum) of the laser line was 6.7 MHz and the OSNR (optical signal to noise ratio) was more than 40 dB.     

Tunable CW alexandrite laser

Wavelength-tunable CW laser action has been obtained from solid-state alexandrite, BeAl2O4:Cr³⁺. Laser emission occurred between 744 and 788 nm with a maximum of 6.5 W observed at the 765 nm wavelength with 3 kW of mercury arc excitation.     

Tunable Y-type waveguide power divider as standard mismatch

A method is proposed for generating standards of voltage standing wave ratio (v.s.w.r.) of values ? 2 by a waveguide device consisting of a Y-type junction matched to the input guide (power divider), with a tunable ratio of power division, an adjustable sliding short circuit and a matched load. A detailed analysis of errors is given, which considers the effects of a possible deviation of the symmetry of the junction and of the uncertainties in the determination of the reflection coefficient and of the position of the short circuit.     

高效率窄线宽光纤激光器

本文报道了一种环形腔掺饵光纤激光器，得到了泵浦效率高达22.6%，输出线宽小于0.1nm的激光输出。     

A single-mode waveguide laser

A laser has been constructed in which a neodymium-doped glass slab forms the core region of a single-mode optical dielectric waveguide. The observed laser output is in a single, spatially coherent, transverse mode, which is characteristic of the waveguide structure, and has a diffraction-limited beamwidth.     

Tunable Q-switched/cavity-dumped Z-fold CO/sub 2/ waveguide laser with two channels and common electrodes

A tunable Q-switched/cavity-dumped z-fold CO/sub 2/ waveguide laser with two channels and common electrodes is studied. The Q-switched and cavity-dumped pulse lasers have been obtained from the z-fold channel with the tunable pulse repetition frequency (PRF) of 1-70 kHz. At the Q-switched operation, the peak power is 730 W and the pulsewidth is 150 ns at the PRF of 10 KHz. At the cavity-dumped operation, the pulse laser width can be adjusted. The peak power is 6000 W with the pulsewidth of 20 ns and 3400 W for 32 ns. CW laser output has been obtained from the other channel and its frequency can be tuned by a piezoelectric transducer. The Q-switched and cavity-dumped pulse laser heterodyne waveforms are observed.