1064nm可编程半导体激光脉冲种子源的研究

为了运用主振功率放大技术获得纳秒量级的高功率密度激光脉冲,设计了一种运用于主振功率放大的半导体激光种子源,通过编程可输出多种形状光脉冲,并采用主动脉冲外形控制技术提高了输出光脉冲的波形质量。实验中研制了高速大电流驱动模块和可编程多种调制波形发生器,并采用了1064nm量子阱分布反馈的大功率半导体激光器。结果表明,该种子源脉冲光功率优于200mW、动态范围优于20dB、脉冲宽度40ns~1μs和重复频率0MHz~5MHz可调,可编程控制输出多种波形。     

Picosecond laser diode pulse amplification up to 12 W by laserdiode pumped erbium-doped fiber

Intense picosecond optical pulse generation from a gain-switched laser diode (LD) was demonstrated using a 1.48-μm LD-pumped Er³⁺ -doped fiber laser amplifier. Saturation characteristics of the amplifier output power were also measured as a function of input repetition frequency. An amplified peak power of 12 W and 105-pJ pulse energy were obtained for 9-ps pulses at a 33-GHz repetition frequency. This is the highest peak power yet demonstrated in pulse generation employing all-laser diodes as active devices     

Generation of picosecond blue light pulse by frequency doubling ofgain-switched GaAlAs laser diode having saturable absorber

Picosecond pulse generation of blue light by frequency doubling of a GaAlAs laser diode is reported. High power pulse generation is realized by incorporating gain switching of a laser diode with a saturable absorber and frequency doubling in a proton-exchanged MgO:LiNbO₃ waveguide. The laser diode with a longer saturable absorber can produce optical pulses with higher peak power and narrower pulse width. The spectral bandwidth of second-harmonic generation for the waveguide is evaluated at about 20 nm. This is wide enough to frequency-double all the multilongitudinal modes of the gain-switched laser diode. A blue light pulse of 7.88-mW maximum peak power and 28.7-ps pulsewidth is obtained for a 1.23-W peak pulse of the laser diode     

高重复频率的增益开关Nd3+:YVO4+KTP绿光激光器

为了设计一种可连续和脉冲双模式输出的绿光激光器,采用一只半导体激光器端面抽运Nd3+:YVO4+KTP胶合晶体,通过腔内倍频,获得光-光转换效率为19%的连续绿光激光输出.利用增益开关技术,改变注入激光器的电脉冲波形,可得到方波、正弦波或三角波的绿光激光脉冲输出;调节激光器驱动电流的幅度和占空比可改变输出激光脉冲的强度和脉宽;改变驱动电源的重复频率可以使输出绿光激光脉冲的重复频率连续可调,最大重复频率可达2MHz.在重复频率为560kHz时,获得了输出绿光激光脉冲宽度为74ns、峰值功率为285mW、振幅噪声小于%.研究表明,利用增益开关技术可以获得重复频率和窄脉冲宽度的绿光激光脉冲.     

Ultrashort Pulses From a Mode-Locked Diode-Oscillator Yb-Fiber-Amplifier System

Ultrashort optical pulses are generated using a hybrid master oscillator power amplifier source. Pulses 2.2 ps in duration generated by a two-contact, bent-waveguide passively mode-locked semiconductor laser are amplified in a ytterbium-doped fiber amplifier to an average power of 0.8 W. External pulse compression yields durations as low as 765 fs with peak powers as high as 0.9kW. Amplification of the harmonically mode-locked diode output has also been demonstrated at the eighth harmonic     

包层抽运调Q光纤激光器的实验研究

报道了几种不同结构的包层抽运调Q光纤激光器。用大功率多模 976nmLD抽运D形内包层掺Yb3 + 光纤 ,对激光器的自调Q ,声光主动调Q ,主被动混合调Q运转状态进行了一系列实验研究。观测分析了调Q光纤激光器的三种阈值情况 ,对它们的输出脉冲特性进行了详细的实验研究。得到了纳秒量级 ,峰值功率～ 2 0 0kW ,重复频率为千赫兹的稳定脉冲序列。对实验结果进行了定性分析     

Continuously wavelength-tunable MQW fabry-perot laser diode pulse source with a fiber-based external cavity

A simple continuously wavelength-tunable fiber ring laser pulse source is demonstrated. Such a source employs a gain-switched multiple quantum-well Fabry-Perot laser diode in a self-seeding scheme and the output pulse wavelength can be tuned continuously via a tunable optical filter. The optical pulses generated exhibit a pulsewidth of 92 ps at the frequency of 2.6 GHz. Within a wide wavelength tuning range of 46 nm, the side-mode suppression ratio and the average power of the output optical pulses obtained are higher than 50.1 dB and 3.3 dBm, respectively, and the pulse spectral stability can be maintained in the whole wavelength tuning range.     

大功率半导体激光侧面泵浦Nd：YAG板条激光器

用准连续６０Ｗ半导体激光侧面泵浦Ｎｄ：ＹＡＧ板条激光器，获得单脉冲能量３．５ｍＪ的激光输出，脉冲重复频率１～１００Ｈｚ，能量输出起伏小于±１％，光－光效率为１５％，斜效率为２９％。实现了声光调Ｑ、电光调Ｑ、ＢＤＮ染料和ＬｉＦ色心晶体被动调Ｑ的激光输出，最大峰值功率超过１００ｋＷ。     

高重复频率的增益开关Nd3+:YVO4+KTP绿光激光器

摘要：介绍了可连续和脉冲双模式输出的绿光激光器。用一只半导体激光器端面抽运Nd3+:YVO4+KTP胶合晶体,通过腔内倍频,获得光-光转换效率为19%的连续绿光激光输出。利用增益开关技术,改变注入激光器的电脉冲波形,可以得到方波、正弦波或三角波的绿光激光脉冲输出;调节激光器驱动电流的幅度和占空比可改变输出激光脉冲的强度和脉宽;改变驱动电源的重复频率可以使输出绿光激光脉冲的重复频率连续可调,最大重复频率可达2MHz。在重复频率为560kHz时,获得了输出绿光激光脉冲宽度为74ns、峰值功率为285mW、振幅噪声小于3%。     

High pak power femtosecond pulses from modelocked semiconductor laser in external cavity

The generation of high peak power femtosecond pulses from an all semiconductor laser system is demonstrated. The system is based on a passively modelocked two-section laser diode in an external cavity, a tapered amplifier and a compact external pulse compressor. Pulse durations are achieved below 600 fs with an average optical power above 500 mW at a repetition rate of 330 MHz. This corresponds to a peak power of 2.5 kW, which is the highest value reported for an all semiconductor ultrafast laser system so far.     

Bistability and optical switching in a polarization-bistable laserdiode

Dependences of the polarization-bistable condition on the coefficients of linear and nonlinear gains of a laser diode are analyzed, including S-shaped and pitchfork types of bistability, in the optical output versus injection current characteristics. Moreover, the steady-state and dynamic characteristics of the optical output for optical input are investigated, taking account of a detuning of incident optical beam from the cavity resonant frequency of a polarization-bistable laser diode, TE-TM polarization switching is shown to be attained in the optical output of the polarization-bistable laser diode in a very fast switching time less than a nanosecond by the application of TE and TM optical input pulses     

Short pulse generation in a visible diode laser by resonantexcitation of a sustained oscillation

A stable 400-MHz train of 670-nm, 100-ps pulses occurs when a gain-guided InGaP-InGaAlP diode laser is modulated in synchronicity with its sustained oscillation. Experimentally, the pulse width decreases and the peak power increases as the RF power increases. At high RF powers, the average output power of the laser shows dips or resonances around those frequencies where short pulses occur     

重复频率连续可调谐的Cr4+:YAG被动调Q微片激光器

激光二极管泵浦的Cr4+:YAG被动调Q微片激光器因其高重复频率、短脉宽、高峰值功率等优点,在光通信、激光雷达、遥感监测、非线性频率变换、激光微加工等领域有着重要应用,然而目前Cr4+:YAG被动调Q激光器脉冲输出稳定性较差,而且重复频率调谐范围窄,限制了其在气溶胶的荧光分析、测距以及空间光通信等领域中的广泛应用。实验中采用预泵浦方式,在激光二极管泵浦的Cr4+:YAG被动调Q微片激光器中获得重复频率连续可调、稳定振荡的激光脉冲输出,重复频率连续可调谐范围为2 ~28 kHz,其单脉冲能量的不稳定性优于2.50%。其中,在重复频率为20 kHz时,获得脉冲宽度为2.431 ns,单脉冲能量17.6 J,消光比252:1的脉冲输出,其幅度不稳定度约为4.00%,重复频率不稳定度约为2.40%。此类宽频可调、稳定振荡的激光二极管泵浦的Cr4+:YAG被动调Q微片激光器有着广阔的应用前景。     

2.79μm Cr,Er:YSGG固体激光器发展现状

2.79 μm激光器在医疗、非线性光学、军事等方面具有重要的应用价值,介绍了Cr,Er:YSGG晶体的物理、化学及激光特性,重点分析了2.79 μm Cr,Er:YSGG固体激光器的发展现状,以及存在的主要问题,阐述了其可能的发展前景。Cr,Er:YSGG激光器可以使用脉冲闪光灯或激光二极管泵浦,并使用电光、声光、被动调Q等方法调Q输出高峰值功率2.79 μm激光,二极管泵浦时激光器可以连续输出。Cr,Er:YSGG晶体的热导率低,泵浦过程中热透镜效应严重,因此,激光器不适合高重复频率工作,输出功率受到一定的限制。实现稳定可靠的2.79 μm调Q巨脉冲激光输出需要解决的关键技术是获得对2.79 μm激光吸收系数小,破坏阈值高的Q开关材料。     

Subpicosecond pulse compression and Raman generation using amode-locked erbium-doped fiber laser-amplifier

Pulses of 20 ps duration from a 1536-nm erbium-doped fiber laser mode-locked at 10 MHz were soliton-compressed in a 1-km fiber to 1.5 ps. The pulses were then amplified in an erbium-doped fiber amplifier and compressed in a second fiber to less than 300 fs. Pulses give rise to stimulated Raman scattering in fibers; the direct output from the erbium fiber laser-amplifier has sufficient peak power to pump fiber Raman lasers. The sources can be made very compact and, with laser diode pumping, an all-fiber design can be realized. Such sources will find use in high-speed optical and electrooptical sampling instrumentation. Peak powers are high enough to study the nonlinear fiber effects that usually require a high-power Nd:YAG or color center laser     

100 W 50 ps gain-switched pulses from vertical-stack laser diode

The advantages of a vertical stack configuration of laser diodes for high peak power, short-pulse generation under fast electrical pumping are demonstrated. 50 ps, 5 nJ optical pulses from a stack of 10 laser diodes have been obtained. This is the best time performance obtained to date from a multi-element gain-switched laser diode     

Generation of low jitter and discrete tunable dual-wavelength optical pulses at arbitrary repetition rates

Recently there is an increasing interest in generatingshort optical pulses with lowti ming jitter and tuneablemulti-wavelength due toitsi mportant applicationin op-tical ti me division multiplexed(OTDM),wavelength di-vision multiplexed(WDM)systems,and opt…     

All-Optical Clock Recovery Using Erbium-Doped Fiber Laser Incorporating an Electroabsorption Modulator and a Linear Optical Amplifier

We demonstrated a 10-GHz all-optical clock recovery system using an erbium-doped fiber laser that incorporates an electroabsorption modulator and a linear optical amplifier. Stable pulses with peak power of 200 mW and pulsewidth of 6 ps are obtained. The output power and the pulsewidth of the recovered clock pulses are independent of the input data pattern. Stable optical clock can still be observed when the input data rate varies by more than 60% of the fundamental frequency without any optical tunable delay line inside the laser cavity. The scheme is essentially wavelength transparent for the whole C-band which recovers clock pulses from input data wavelength between 1525 and 1565 nm     

The effects of a detuned optical input on bistable laser diodeswith inhomogeneous current injection

The effects of an external optical input on a bistable laser diode (BLD) with inhomogeneous current injection are discussed. The bistable behavior of optical output versus injection current is shown to be variously modified, depending on the wavelength and power of the optical input. Optical set and reset operations and optical logic achieved by optical input pulses can be explained by these characteristics of a BLD modified by an external optical signal. Analysis using rate equations is also offered to help interpretation of experimental results, as well as the optical output and the bias current injected into the BLD     

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