Simultaneous Mode-locking Research Articles

Passive mode-locking and Q-switching of high power lasers by means of the optical Kerr effect

A new passive method for simultaneous mode-locking and Q-switching in high power lasers is described. In order to obtain the desired effects, the intensity dependent refractive index n (i.e., the optical Kerr effect) in a liquid consisting of anisotropic molecules is used in a twofold way. This is achieved in a single device, here called the “Opto-Optical Modulator” (OOM). The main advantages of the OOM are: (a) it is generally applicable in high power lasers, (b) it is possible to change the transmission property of the OOM considerably and thereby the characteristics of the generated mode-locked pulse train, (c) it is possible to continuously vary the pulse duration of the mode-locked pulses by varying the temperature of the Kerr active medium in the OOM, and (d) it is possible to stabilize the peak amplitude of the mode-locked pulses.

SIMULTANEOUS MODE-LOCKING AND SECOND-HARMONIC GENERATION BY THE SAME NONLINEAR CRYSTAL

Simultaneous mode-locking and quasi cw second-harmonic generation (SHG) in high-temperature lithium niobate or barium sodium niobate of a Nd3+:YAG laser have been accomplished by electro-optic modulation of the nonlinear medium. This technique will be useful for obtaining ``100% conversion efficiencies,'' which would not be possible by the standard intracavity method, with nonlinear crystals that are either too short or have too low a nonlinear coefficient to achieve optimum coupling of the laser.