用腔内半导体可饱和吸收镜钛宝石激光器中自锁模状态的实验研究

用可饱和吸收体镜(SESAM)的掺钛蓝宝石激光器能够稳定运转在三种不同的锁模状态,即可饱和吸收体被动锁模、孤子锁模加被动锁模和KLM锁模.分析了三种自锁模的机理和SESAM的作用.对SESAM实现KLM锁模的自启动机制进行了实验观察和讨论.从该激光器的KLM锁模状态,获得了小于18飞秒的锁模脉冲序列. 关键词： 半导体可饱和吸收镜 自锁模 钛宝石激光器     

直接从钛宝石激光器获得超连续光谱

采用啁啾镜和棱镜对相结合补偿色散的方法在自调Q自锁模钛宝石激光器腔内直接产生了超 过一个倍频程的超连续光谱，光谱范围从460nm到1000nm；这是飞秒激光器输出光谱在短波 波段第一次突破500nm.这将使得脉冲的载波包络偏移频率的测量装置得到大大简化，同时也 提高了光频测量的稳定性. 关键词： 超连续光谱 啁啾镜 自调Q自锁模 钛宝石激光器     

高精度单激光脉冲选择器及同步触发系统

 通过选择高速、高性能的ECL电路和采取多个半导体雪崩三极管的串并联及整形锐化等措施, 与两个并联的普克尔盒组成高精度电光开关,准确地从钛宝石自锁模激光器输出的82MHz飞秒激光脉冲序列中选出了单个脉冲。     

三波长单腔型自锁模飞秒钛宝石激光器

在我们优化的自锁模飞秒钛宝石腔型结构的基础上,实现了一台三波长单腔型自锁模飞秒钛宝石激光器,该台激光二器不仅据我们所知首次实现了三波长飞秒光脉冲的同时运转,而且它还具有可调谐、阈值低、输出功率高及易于调整、结构简单等特点.     

腔内型光电导太赫兹辐射产生器设计

提出了在飞秒锁模钛宝石激光器腔内产生太赫兹辐射的新设计方案,并给出了太赫兹产生器件的结构参数以及器件的设计原理.新设计的器件把光电导太赫兹偶极天线发射器与飞秒钛宝石激光器的可饱和Bragg反射镜结合在一起,不仅可以提高太赫兹辐射的产生效率,而且可以使飞秒钛宝石激光器自启动锁模.     

由自锁模钛宝石激光器产生19fs脉冲

由自锁模钛宝石激光器产生１９ｆｓ脉冲林位株，赖天树，陈毓川，郑向阳，徐杏绍，莫党（中山大学物理系，广州５１０２７５）自锁模钛宝石激光器是９０年代发展起来的新型固体可调谐激光器，它以其激光频谱调谐范围宽、能够产生飞秒级短脉冲、输出功率高、装置简单和工作...     

亚10 fs激光脉冲产生中的受激拉曼散射与四波混频效应

自行搭建的自锁模钛宝石激光器工作在下稳区的上边界附近,采用熔融石英棱镜对在激光器谐振腔的腔内和腔外同时进行群速度色散补偿.随着腔内棱镜对提供色散补偿的变化,输出激光脉冲的频谱会突然展宽至664—840nm,其空间模式也由基横模变化至衍射环状结构,这是受激拉曼散射和四波混频效应导致锁模激光脉冲频谱进一步展宽的结果.在此状态下自锁模钛宝石激光器可实现670—865nm范围的波长调谐.如此宽的频谱为钛宝石激光器产生亚10fs激光脉冲提供了必要的条件. 关键词： 飞秒激光脉冲 受激拉曼散射 四波混频 群速度色散     

钛宝石飞秒激光器的锁模机理探讨

测量了X型折叠腔钛宝石飞秒激光器的发光动力学曲线，并运用传播圆 变换圆图解分析方法，系统地探讨了钛宝石飞秒激光器的自锁模机理和过程，提出了一种新的锁模机理——自脉动克尔透镜开关放大锁模. 关键词： 传播圆 变换圆 自脉动克尔透镜开关放大锁模 光学混沌     

利用SBR实现自启动锁模钛宝石飞秒激光脉冲的产生

利用国内生长的低损耗双量子阱结构的可饱和布拉格反射器在掺钛蓝宝石激光器中实现了可饱和吸收体被动锁模、孤子锁模和KLM锁模状态的自启动稳定运转.当抽运功率为4.5W时，用啁啾镜进行色散补偿，获得了18fs的KLM锁模脉冲，输出功率为150mW. 关键词： 可饱和布拉格反射器 啁啾镜 飞秒 钛宝石激光器     

用于飞秒脉冲锁模激光器中的优化Gires-Tournois反射镜

根据飞秒脉冲锁模钛宝石激光器腔内色散补偿的要求,设定负色散镜的色散目标值,用最优化方法,设计出了负色散Gires-Toumois(G-T)反射镜,计算了光场在优化负色散G－T反射镜不同膜层内的分布,不同波长的光场分量,在优化负色散G－T反射镜内部,穿透深度不同,在720nm-900nm波长范围内,长波分量有较大的穿透深度,因而对长波分量提供较大的时间延迟,将其用于飞秒锁模钛宝石激光器中,取代传统的腔内色散补偿棱镜对,结合半导体可饱和吸收镜（SESAM）自启动锁模,在钛宝石激光器中获得了56fs脉冲。     

频域标定飞秒脉冲干涉自相关迹及钛宝石振荡器实时啁啾监测

采用频域处理的方法首次在频域标定飞秒激光脉冲干涉自相关迹的时间扫描.计算被测脉冲的均方根宽度和啁啾参数，并以此为依据在实验中优化钛宝石振荡器的调节从而获得接近变换极限的115fs脉冲.该方法只涉及到数值积分和快速傅里叶变换，在实验中完全可以用于实时监测振荡器的运行情况. 关键词： 频域标定 钛宝石振荡器 飞秒脉冲 干涉自相关迹     

Passive synchronization of two independent laser oscillators with a Fabry-Perot modulator

By optical modulation of the reflectivity of an intracavity nonlinear Fabry-Perot semiconductor mirror, the pulse train from a passively mode-locked picosecond Nd:YVO(4) laser oscillator is synchronized to an independent femtosecond-mode-locked Ti:sapphire laser. We obtain stable synchronized pulse trains at central wavelengths of 1064 and 850 nm, and the Ti:sapphire laser is still independently tunable over a large wavelength range. The tolerable cavity-length difference between the two laser oscillators exceeds 20mu;m .     

Carrier-envelope phase-controlled quantum interference of injected photocurrents in semiconductors

We demonstrate quantum interference control of injected photocurrents in a semiconductor using the phase stabilized pulse train from a mode-locked Ti:sapphire laser. Measurement of the comb offset frequency via this technique results in a signal-to-noise ratio of 40 dB (10 Hz resolution bandwidth), enabling solid-state detection of carrier-envelope phase shifts of a Ti:sapphire oscillator.     

用SPIDER法测量超宽带钛宝石振荡器的激光脉宽研究

用SPIDER方法测量了超宽带钛宝石振荡器输出激光的脉宽，得到7.86 fs的测量结果，这是目前国内所报道的仅用啁啾镜补偿色散、直接从振荡器输出的最短激光脉冲.简要介绍了振荡器的基本结构和SPIDER方法测量装置，并对计算得到的光谱相位进行了讨论和分析.     

Tunable light source for coherent anti-Stokes Raman scattering microspectroscopy based on the soliton self-frequency shift

We present a photonic crystal fiber (PCF)-based light source for generating tunable excitation pulses (pump and Stokes) that are applicable to coherent anti-Stokes Raman scattering (CARS) microspectroscopy. The laser employed is an unamplified Ti:sapphire femtosecond laser oscillator. The CARS pump pulse is generated by spectral compression of a laser pulse in a PCF. The Stokes pulse is generated by redshifting a laser pulse in a PCF through the soliton self-frequency shift. This setup allows for probing up to 4000 cm(-1) with a spectral resolution of approximately 25 cm(-1). We characterize the stability and robustness of CARS microspectroscopy employing this light source.     

Compression of long-cavity Ti:sapphire oscillator pulses with large-mode-area photonic crystal fibers

Motivated by the pulse compression challenge of novel long-cavity, high-pulse-energy Ti:sapphire laser oscillators, we report on ~280 nm supercontinuum generation and 4.5-times compression of close to transform limited, high-energy oscillator pulses using different large-mode-area photonic crystal fibers and standard chirped mirrors. As input, we used pulses of a long-cavity Ti:sapphire oscillator with 190 nJ pulse energy, 70 fs pulse length and 3.6 MHz repetition rate. Compressed pulses at the fiber/compressor output had a duration of 15–18 fs with up to 100 nJ pulse energy representing as much as 53 % throughput for the fiber/chirped mirror system. Using transform-limited input pulses, we could use short fiber pieces and thus a simple, low-dispersion chirped mirror compressor comprised of one pair of mirrors.     

Design of the Seed Source for High Power KrF Excimer Laser System

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Generation of 7-fs laser pulse directly from a compact Ti:sapphire laser with chirped mirrors

A compact femtosecond Ti:sapphire laser resonator consisting of three chirped mirrors and one output coupler was designed. By accurately balancing the intra- cavity dispersions between Ti:sapphire crystal, air and chirped mirrors, we directly generated the laser pulse shorter than 7 fs at the average power of 340 mW with 3.1 W pump. The repetition rate of the laser oscillator is 173 MHz at the centre wavelength of 791 nm, and the ultrabroaden spectrum covers from 600 nm to 1000 nm. To the best of our knowledge, this is the simplest laser resonator capable of generating sub-10 fs laser pulse.     

Sub-6-fs pulses from a SESAM-assisted Kerr-lens modelocked Ti:sapphire laser: at the frontiers of ultrashort pulse generation

Well-characterized pulses in the two-optical-cycle regime are demonstrated using a Kerr-lens modelocked (KLM) Ti:sapphire laser and phase-sensitive diagnostics. The oscillator employs double-chirped mirrors (DCMs) for dispersion compensation, spectral shaping via wavelength-dependent output coupling, and a semiconductor saturable absorber mirror (SESAM) for reliable operation at up to 300 mW output power and with a repetition rate of ~90 MHz.In the discussion of the experimental results we emphasize how spectral shaping can be used most efficiently in the generation of the shortest possible pulse supported by the Ti:sapphire gain bandwidth.