A ruby laser with passive Q-switch element

The generation of giant impulses was observed experimentally in a medium consisting of two elements — a ruby single crystal and a plane-parallel glass plate. The dependence of the switch element on the intensity of the light ray was investigated. A semi-transparent mirror was realized by plates made from quartz or heavy flint glass. The results are compared with dielectric mirrors.The authors would like to thank Ing. Nebenský for helpful discussion, workers of Dioptra Turnov, national enterprise, for making the filters and grinding the plates, and T. Daíek and A. Novotný for help in the measurements.     

利用被动锁模技术实现超短脉冲激光输出实验

基于被动锁模技术,设计了结构紧凑的Z型谐振腔,采用半导体可饱和吸收镜作为被动锁模元件,利用激光二极管泵浦增益线宽较宽的Nd∶YVO4晶体,最终实现了连续锁模的脉冲输出.在输入功率为8.20W时,获得了输出功率为1.72W的1 064nm连续锁模脉冲激光输出,光-光转换效率达21%,锁模脉冲重复频率为110MHz.     

Infrared fluorescence and laser action of fast mode-locking dyes

Fluorescence spectra in the near infrared are observed of the dye Eastman 9860 and of new, faster mode-locking dyes. The quantum efficiencies are determined to be small with η≃10⁻³. The short fluorescence lifetimes are deduced from optical gain measurements. The fluorescence time-constants are found to have the same value as the corresponding absorption recovery times. Even laser action is observed in these fast saturable absorbers previously belieyed to be non-fluorescent.     

Toward higher-order passive harmonic mode-locking of a soliton fiber laser

We report >13 MHz/mW pump power efficiency in increasing the repetition rate of passive harmonic mode-locking by engineering the soliton pulse energy in Er fiber lasers incorporating carbon nanotube saturable absorber. Stable pulses with a ～5 GHz repetition rate and 40 dB of super-mode suppression are demonstrated with only ～400 mW pump power in a single-clad fiber laser.     

Theory of passive mode-locking of CW dye lasers with contacted and non-contacted absorbers

A theoretical treatment of the influence of a saturable absorber in close contact with a highly reflecting mirror on a light pulse is given. The shaping of a Gaussian pulse during a single passage through such an absorber is calculated for various absorber lengths. The influence of absorber position and length on the pulse parameters and the stability of a continuously pumped dye laser are investigated. The shortest pulses and the most favourable operation conditions of the laser are to be expected in the case of a short contacted saturable absorber.     

Passive mode-locking of a ruby laser using low-frequency stimulated brillouin scattering in birefingent crystals

A new technique of mode-locking Q-switched lasers using a birefringent crystal as an intracavity element is reported. Intense elastic waves are generated inside a birefringent crystal through the low-frequency, stimulated Brillouin scattering process and these in turn modulate the refractive index of the crystal and thus provide the necessary phase synchronization for mode-locking. Strong coupling between several neighboring modes of the laser is evidenced by the observation of high pulse repetition rates (several pulses circulating simultaneously within the cavity).     

Computer simulation of passive mode-locking of dye lasers with consideration of coherent light-matter interaction

A numerical model of passive mode-locking of dye lasers is presented, which allows the calculation of the steady state pulse parameters without any limitation to pulse energy and duration. The solutions are compared with previous analytical results based on a rate equation treatment (i.e. without considering the phase memory). The pulse evolution and the influence of cavity dumping on the steady state are discussed.     

New dye solutions for mode-locking infrared lasers

The recovery time of saturable absorbers is shortened externally by electronically active solvents, e.g., iodoethane, methyl sulfoxide, or ethyl sulfide. With a highly stable dye in such a solvent, very reproducible mode-locking of the neodymium-glass laser is achieved. The recovery time of the dye and hence the degree of mode-locking can be varied readily through the choice of solvent or solvent mixture.     

10 GHz passive harmonic mode-locking in Er-Yb double-clad fiber laser

In this paper we report passive harmonic mode-locking of an Erbium/Ytterbium-doped double-clad fiber laser with repetition rates up to 10 GHz. The modes synchronization was obtained using Nonlinear Polarization Rotation mechanism. The stable operation at 634th harmonic of the fundamental (15.8 MHz) repetition frequency was achieved. Soliton pulses with the duration of less than 900 fs and 300 mW average output power were obtained.     

Investigation of Cr:YAG passive mode-locking in a pulsed Nd:YAG laser

Passive mode-locking of a pulsed Nd:YAG laser using a Cr⁴⁺:YAG saturable absorber was realized for the first time in a nearly critical stable resonator containing an antiresonant ring structure. The output energy and pulse duration are 13.5 mJ and 180 ps, respectively. The recovery time and saturable intensity for excited-state absorption of Cr⁴⁺:YAG under the action of strong laser pulses were calculated from rate equations.     

Novel method for active mode-locking and tuning of dye lasers

A novel method of tuning an active mode-locking of dye lasers is described using a new type of interferometer. Preliminary results using a flashlamp-pumped dye laser demonstrate the capabilities of the method.     

碰撞锁模环形染料激光器动力学过程的研究

本文在建立碰撞锁模(CPM)激光器数学模型的基础上,对碰撞锁模激光器中激光锁模脉冲形成的动力学过程进行了计算机模拟计算,并对其结果进行了理论分析和讨论,得到了脉冲宽度、脉冲波形及对称性与泵浦速率、腔长、增益介质和可饱和吸收介质在腔内的相对位置等因素间的关系。