Over 1100 nm wavelength tuning in superstructure grating (SSG) DBR lasers

A broad range tuning of over 100 nm in tunable DBR lasers with superstructure grating (SSG) is reported. The SSG reflectors for 100 nm were designed and patterned by electron beam lithography. 1.55 mu m DBR lasers with SSG reflector operate in a single mode with a tuning range of 83 nm under CW conditions. With inclusion of the multimode operating region, the tuning range becomes as wide as 103 nm.<>     

DBR单纵模光纤激光器波长温度调谐

报道了采用DBR方式,利用8 mm的高浓度掺Yb3+单模光纤,实现了波长为1 064 nm的单纵模调谐激光稳定输出的实验结果。该DBR谐振腔有效腔长为16 mm,输出最大功率为7.4 mW,通过半导体制冷器温控改变谐振腔的温度,实现了0.824 nm的单纵模无跳模调谐。采用光纤外差法,并利用低损耗环形器和光纤反射镜倍增延迟线长度提升测量精度的方式,测量得到激光最大线宽为4.4 kHz。单纵模激光的弛豫震荡峰位于900 kHz处,其相对强度噪声为-110 dB/Hz,当频率大于1.5 MHz时相对强度噪声为-145 dB/Hz。     

1318.8nm单一谱线Nd:YAG激光器

为有效抑制1064nm和1338nm谱线振荡,采用三色镜技术,实现了Nd:YAG单一谱线1318.8nm激光准连续运转,抽运功率为2100W时,激光输出功率为122W,电光转换效率为5.8%,斜率效率为8.22%,激光输出功率不稳定度≤±5%,激光阈值功率约为500W。该激光系统结构简单,工作稳定,在激光医疗、国防安全等领域具有应用价值。     

1338nm单一谱线Nd:YAG激光器

通过控制介质膜系在不同波长的透过率,实现了Nd YAG单一谱线13 3 8nm激光运转,抽运功率为2 2 0 0W时,激光输出平均功率为10 2W ,电-光转换效率为4.6% ,斜率效率为6.3 % ,输出功率不稳定度≤±5 %。激光阈值功率约为40 0W。     

Circular grating coupled DBR laser with integrated focusing outcoupler

We report on the fabrication and operation of a circular grating coupled, AlGaAs-InGaAs surface-emitting distributed Bragg reflector (DBR) SQW laser with an integrated focusing outcoupler. Electron beam lithography and reactive ion beam etching were used to fabricate the laser with a first-order resonant grating for optical feedback and a separate detuned, chirped second-order grating for outcoupling and focusing the beam.     

Widely tunable sampled grating DBR laser with integratedelectroabsorption modulator

We report on the development of the first widely tunable semiconductor laser with an integrated electroabsorption modulator. The laser is a four-section buried-ridge sampled-grating distributed Bragg reflector design. It has a 41-nm continuous tuning range with a maximum tuning current of 23.5 mA for the hack mirror and 21 mA for the front mirror. The modulator is based on a 0.87-eV bandgap bulk waveguide structure. It is capable of producing more than 22 dB of optical extinction over the entire tuning range of the laser with a -4.0-V bias     

Wide continuous wavelength tuning of a narrow linewidth DBR laser

A continuous wavelength tuning range of 5.4 nm is obtained for a three-section DBR (distributed Bragg reflector) laser by applying one control current in both forward and reverse bias directions. In the reverse direction no significant linewidth broadening is seen due to the absence of injection-recombination shot noise, and a linewidth of less than 3 MHz is obtained over a wavelength span of 1.8 nm. The minimum linewidth observed is 580 kHZ     

561 nm全固态单纵模激光器

报道了一台激光二极管端面泵浦的全固态、单纵模561 nm黄光激光器。采用镀制窄带反射膜的方法来抑制增益较大波长的起振,并通过I类临界相位匹配LBO晶体腔内对1123 nm 基频光倍频及V型腔结构,选择单一波长运转,进一步通过F-P标准具选频方法,获得 561 nm 单纵模激光的稳定输出。在泵浦功率为2.4 W时,获得了80 mW的561 nm单纵模激光,光-光转换效率为3.3%,纵模线宽为24.1 MHz。该激光器在人眼黄斑病变治疗仪及流式细胞仪等生物医学领域,具有很高的实用价值,是近年全固态激光器的研究热点之一。     

Simultaneous fast wavelength switching and intensity modulationusing a tunable DBR laser

The use of a three-section distributed Bragg reflector (DBR) laser to switch wavelengths rapidly and simultaneously transmit data by intensity modulation is discussed. This combination simulates the operation of a tunable transmitter in a multiwavelength packet switch. In this type of switch, each output port is tuned to receive data on a unique, fixed wavelength; packets are routed from input ports to the appropriate output ports by wavelength addressing. In each transmission cycle, the input port transmitter tunes to the wavelength associated with the intended output port and subsequently broadcasts the data packet. Limitations on various system parameters, such as the number of allowed channels, the wavelength switching times, and packet lengths (residency times), as determined by thermally-induced wavelength drifts are also discussed. The advantages of using a single device for both fast wavelength switching and direct data modulation are significant: the elimination of external modulators improves both the simplicity of the implementation and the available power budget     

Wideband wavelength tunable modelocked fibre laser over 1557-1607nm

An electronically wavelength tunable modelocked fibre laser operating over a 50 nm range using an all-fibre acousto-optic tunable filter is presented. The tuning range is 1557-1607 nm, for a 70 m long erbium-doped fibre (EDF) with a 270 ppm concentration     

Optical high-frequency pulse generation with wavelength tunability by using a DBR laser with vernier-type gratings

An optical high-frequency pulse generation method with wavelength tunability is presented by taking advantage of vernier-type gratings in a distributed Bragg reflector laser diode. Experimental results showed that sinusoidal optical pulses, whose lasing wavelengths were tunable, were created with repetition frequencies around 30 GHz. The widths of the radio frequency spectra, furthermore, were drastically reduced by means of mode locking with externally injected optical pulses.     

Compact high-energy Q-switched cladding-pumped fiber laser with atuning range over 40 nm

We describe a compact Q-switched diode pumped double-clad ytterbium-doped fiber laser. The fiber laser was bidirectionally pumped by two laser diodes (2 W of output power each) via two side-injecting pump-couplers. We used a large multimode core of 15 μm diameter to increase the laser gain volume and thus to achieve higher pulse energy. Experimentally this laser produced pulses with energy up to 170 μJ with a peak power of 2 kW (at a low repetition rate of 500 Hz) and was tunable from 1060 to 1100 nm     

DBR laser with nondynamic plasma grating formed by focused ion beamimplanted dopants

A static plasma grating has been demonstrated experimentally (see M.C. Wu et al., Appl. Phys. Lett., vol.53, no.4, p.265-7, 1988) in a large-optical-cavity focused-ion-beam-distributed-Bragg-reflector (FIB-DBR) GaAlAs/GaAs laser diode. The grating is formed by implanting stripes of dopants with a focused ion beam. The dopants ionize to form periodic fluctuations in the carrier concentration which, through the Kramers-Kronig relations, form an index grating. A model of the grating strength for optimization of the laser design is developed and presented. The computed results show that the coupling coefficient k can be increased by more than an order of magnitude over the 15 cm ¹ experimentally. Therefore, FIB-DBR (or FIB-distributed-feedback (DFB)) lasers with performance comparable to that of conventional DBR (or DFB) lasers can be expected     

Sampled grating DBR laser arrays with adjustable 0.8/1.6 nmwavelength spacing

The difficulty in fabricating multiwavelength laser arrays with uniform wavelength spacing is overcome by using sampled grating distributed Bragg reflector (DBR) lasers as the constituent of a laser array. The sampling periods of the DBR mirrors are varied from laser to laser to provide reflection combs with different spacings in wavelength. Arrays of twelve lasers have been successfully fabricated with a single holographic exposure step. The wavelength spacing among the lasers can be adjusted to be around 0.8 or 1.6 nm with a simple tuning mechanism     

Sampled grating tunable twin-guide laser diodes with over 40-nm electronic tuning range

Device and tuning characteristics of sampled grating tunable twin-guide laser diodes are presented. The vertically integrated, monolithic widely tunable laser requires only two tuning currents to fully cover a wavelength range of more than 40 nm by electrooptic tuning. Its tuning behavior is quasi-continuous with up to 8.2-nm broad continuous tuning regions. High sidemode suppression (SMSR /spl ges/ 35 dB) as well as large output power (P /spl ges/ 10 mW) are obtained over the wavelength range from 1520.5 to 1561.5 nm.     

利用光栅测量远场入射激光波长的方法研究

依据光栅衍射原理,采用电荷耦合器件CCD作为探测器,通过测量入射激光成像点在电视靶面坐标系中的脱靶量,确定光栅的入射角和衍射角,提出了一种利用固定式平面反射光栅测量远场未知方位入射激光波长的方法。介绍了该方法的原理及光学系统结构,阐述了成像点脱靶量与光栅入射角和衍射角的关系,推导了入射激光的波长计算公式,结合光学系统的结构给出了计算波长测量误差的表达式。远场测量模拟实验验证了该方法的可行性。     

Chirped waveguide grating router multifrequency laser with absolute wavelength control

We apply chirping of the waveguide grating router to the multifrequency laser (MFL). We present a 10/spl times/100 GHz chirped MFL that has precise absolute oscillation wavelength control and guaranteed single router free-spectral-range mode oscillation for all 10 channels and, additionally, guaranteed single cavity mode oscillation for 4 of the channels.     

High-power single mode InGaAs/AlGaAs laser diodes at 910 nm

Single mode laser diodes have been fabricated from pseudomorphic InGaAs/AlGaAs quantum well epitaxial material operating up to 350 mW CW. The laser output is a single transverse and longitudinal mode to 180 mW, while the spectral output is centred near 910 nm.<>     

Transform-limited optical short-pulse generation at high repetitionrate over 40 GHz from a monolithic passive mode-locked DBR laser diode

The fabrication of monolithic InP-based passively mode-locked distributed-Bragg-reflector (DBR) laser is reported. An optical short-pulse train with a duration of 3.5 ps was generated at a repetition rate of over 40 GHz. The time-bandwidth product was 0.43, and it was very close to the transform-limited value of a Gaussian waveform. Peak power of 60 mW has been achieved. This laser is promising as an optical source for a high-bit-rate soliton transmission system