Tunable ultraviolet generation using a femtosecond 250 kHzTi:sapphire regenerative amplifier

A mode-locked Ti:sapphire regenerative amplifier system pumped with a single argon ion laser produces μJ energy femtosecond pulses of 800 nn wavelength at up to 300 kHz repetition rate. This output is used to generate tunable femtosecond pulses in the ultraviolet to as short as 240 mn by using a combination of harmonic generation, white-light continuum generation and parametric amplification. A variety of techniques to access different parts of the UV spectrum are presented     

Tunable femtosecond soliton generation in Ge-doped fibre

In contrast to conventional polarisation maintaining fibres, a simple Ge-doped singlemode fibre is used to generate tunable femtosecond soliton pulses. Soliton self-wavelength-shift up to 200 nm is achieved in a 17 m-long fibre. The generated 'monocoloured' soliton pulses have quasi-ideal sech/sup 2/ spectral shapes.     

Tunable near-infrared femtosecond soliton generation in photoniccrystal fibres

Femosecond Raman soliton generation, tunable from 850-1050 nm, has been demonstrated by pumping untapered photonic crystal fibre with 110 fs pulses from a modelocked Ti:sapphire laser. Experimental results are in excellent agreement with the results of numerical simulations using an extended nonlinear Schrodinger equation     

Picosecond and femtosecond pulse generation in a regenerativelymode-locked Ti:sapphire laser

The authors have produced transform-limited pulses ranging from 100 ps to 40 fs duration from a Ti:sapphire laser. Output powers in excess of 1 W and peak powers of 0.5 MW have been observed. They describe the technique of regenerative mode locking and present evidence that a transient with a peak power of more than 10 kW is required to initiate mode locking. The role of group velocity dispersion is highlighted and a value of -750 fs² is measured for the group delay dispersion in an operating laser. The authors describe the limits on both the power and pulsewidth obtainable from this laser and present pulse compression experiments which produce 17 fs pulses with 70 mW of average power     

Tunable infrared parametric generation in cesium dihydrogen arsenate

Parametric generation of near infrared coherent light, tunable over the range 854-1410 nm, was obtained in an oscillator using a 3-cm crystal of cesium dihydrogen arsenate (CDA). Pumping was accomplished with 10-ns pulses of 532-nm light from a frequency-doubled Nd:YAG laser. Single-pass parametric gains of the order of 300 were obtained in the crystal. The infrared output pulses typically were 1 ns in duration, with a peak power of approximately 600 kW.     

Ti：Al_2O_3可调谐激光器模式研究

从高斯光束的理论出发，研究了Ｔｉ：Ａｌ_２Ｏ_３激光器中各参数间的相互关系，引入了Ｋｅｒｒ非线性透镜效应的影响。根据理论分析的结果，设计可调谐谐振腔，获得了最大可调谐输出能量７７．３ｍＪ，波长可调谐范围６５０～１０３９ｎｍ，光束发散角约为１ｍｒａｄ的ＴＥＭ_００模激光输出。     

可调谐Ti：Al2O3激光器

本文以速率方程为基础对脉冲Ti:Al_2O_3激光器进行了初步的研究,并对输出激光与泵浦光之间的时间延迟以及激光器的特性进行探讨,给出了实验结果。     

可调谐的双波长钛宝石激光器

一台可调谐钛宝石激光器两个波长同时运转,在数ns以内同步,相对波长差最大可达55nm。观测到明显的两种波长激光的竞争和关联。由BBO实现了两波的和频与倍频。     

Tunable, picosecond pulse generation using a compressed, modelockedlaser diode source

The generation of pulses shorter than 6 ps, tunable from 1.26 to 1.32 μm, is discussed. The source of these pulses consists of a mode-locked external-cavity 12.3-μm InGaAsP diode laser with grating feedback combined with a compressor which is a grating pair containing an internal telescope. The dispersion in the compressor can be tuned in both magnitude and sign to optimally compensate the chirp in the mode-locked external cavity laser at each wavelength     

准连续可调谐钛宝石激光器

报道了一种结构新颖紧凑．稳定可靠，具有单模输出、窄线宽、波长覆盖范围宽、连续可调谐、泵浦效率高等特点的钛宝石激光器。     

Tunable dual-wavelength picosecond pulse generation using multiple-optical-path self-seeding approach

A simple system is developed to generate tunable dual-wavelength optical pulses by self-injection seeding of a laser diode. The wavelengths are selected by controlling two light paths incident on a single diffraction grating. The spectral separation has been tuned from 1.8 to 16.1 nm while maintaining an output side-mode-suppression-ratio (SMSR) over 21 dB. This multiple-optical-path self-seeding approach is simple and efficient, thus providing an attractive alternative to generate tunable multiwavelength pulses.     

掺钛宝石可调谐激光器进展

本文评述钛宝石晶体和激光器的特性和进展。讨论若干基本技术问题,包括泵浦源和晶体元件的选择、激光器设计中的一些关键参数;涉及光纤耦合输出及由BBO作倍频。展望其未来发展。     

Ti：Al2O3可调谐激光器综述

掺钛蓝宝石(Ti∶AI_2O_3)是一种高增益、宽荧光辐射范围的激光晶体。Ti∶Al_2O_3可调谐激光器1982年问世以来发展极为迅速,已能提供从可见到近红外的会波段可调谐激光,单脉冲输出能量6.5J,连续输出功率巳达17W。国际上,敏宝石晶体和钛宝石可调谐激光器已有商品。第一台全固化可调谐激光系统已研制成功。     

Tunable infrared modulator and switch using Stark shift in stepquantum wells

A tunable infrared modulator and/or switch using intersubband Stark shift in a step quantum well is discussed. The device utilizes the intersubband absorption and the large change of separation between energy levels in the step quantum well under an applied electric field. The incident infrared beam on the device is either absorbed or transmitted depending on the energy separation of the levels, and thus the modulation can be achieved by adjusting the energy levels with an applied electric field. The extremely short lifetime of the intersubband transition makes this modulator suitable for application in high-speed long-wavelength optical communications     

可调谐脉冲钛宝石光纤激光器

报道了用脉冲调Ｑ－Ｎｄ：ＹＡＧ激光器倍频泵浦的掺钛宝石光纤激光器。在一根φ３５０μｍ×１１．２ｍｍ的光纤中获得了０．５ｍＪ的泵浦阈值、１５μＪ的输出能量以及５６．５ｎｍ的调谐范围。     

宽调谐窄线宽脉冲钛宝石激光器

介绍了一种采用色散型布儒斯特棱镜扩束器调谐的脉冲钛宝石激光系统，通过泵浦光反馈泵浦，使转换效率提高了～８％；采用色散型布儒斯特棱镜扩束器加光栅（或平面镜）调谐，实现了窄线宽可调谐输出，输出激光能量为２３ｍＪ，转换效率达１９％．调谐范围为６８０～９１３ｎｍ，输出激光线宽小于０．０１ｎｍ。     

Tunable external-cavity semiconductor laser using monolithicallyintegrated tapered amplifier and grating coupler for collimation

A novel lensless tunable external-cavity laser using monolithically integrated tapered amplifier, grating coupler (GC) and an external half mirror is proposed and demonstrated. It can be fabricated by a simple process and emits a collimated output beam. By making use of wavelength dispersion of the GC, the lasing wavelength can be angle tuned. Wavelength tuning over a wide range of 21.5 nm by 4.5° device rotation and an 84-mW output power were achieved under continuous-wave operation. A well-collimated output beam with a divergence angle as small as 0.3° was maintained over the entire tuning range     

Tunable transform-limited pulse generation using self-injectionlocking of an FP laser

Wavelength-tunable, near transform-limited pulses have been generated using a Fabry-Perot laser diode coupled to a fiber loop containing a fiber Fabry-Perot resonator (FFPR) and a polarization controller. The ratio of transmitted to reflected light from the loop can be adjusted using the polarization controller. Single-mode operation of the gain-switched laser is achieved by self-injection locking, which is induced by light reflected from the fiber loop. The resulting output pulse has a time-bandwidth product of 0.4 and is tunable over about 15 nm by varying the tuning voltage of the FFPR     

A femtosecond waveform transfer technique using type II second harmonic generation

We present a novel waveform frequency conversion technique by type II second harmonic generation (SHG). We have theoretically studied and experimentally demonstrated femtosecond waveform transfer from 800 to 400 nm wavelength by type II SHG in a lithium triborate (LBO) crystal. The output second harmonic (SH) waveform is a temporally magnified or compressed version of the input fundamental waveform, depending on the experimental configuration. Our experiments demonstrate that this technique can transfer not only the intensity profiles of the fundamental waveform, but also the phase profiles. This technique shows promise for programmable generation of shaped ultrafast optical waveforms down to the UV range, where direct pulse shaping is challenging.     

多波长可调谐Ti：Al_2O_3飞秒激光器的研究

研制出一种多波长可调谐自锁模Ｔｉ：Ａｌ２Ｏ３激光器．能够同步产生二个或三个波长的飞秒脉冲序列．最短脉冲为４８ｆｓ，平均功率为７０ｍＷ．脉冲中心波长间距在２６～４９ｎｍ范围内可变。激光器波长调谐范围为７５０～８３０ｎｍ。