LE-0800 Generation of Q-Switch Laser Pulses

A. LE-0800 Generation of Q-Switch Laser Pulses with saturable absorber

B. Combination of passive q-switch and intra-cavity frequency doubling crystal

C. LE-0800 Generation of Q-Switch Laser Pulses with Pockels's cell

The use of short-pulse lasers enables the generation of high peak power pulses in a short time, which are useful for the investigation of non-linear effects and for the investigation of time dependent effects e.g. time resolved spectroscopy. In order to achieve extremely high peak power up to the Gigawatt range, laser systems are applied, which possess long lived excited states able to store energy and to emit it in an extremely short time. One of such lasers is e.g. the Nd:YAG laser. With q-switching in so called active or passive mode, it is possible to generate such short pulses. Here, in a first step the theory of laser operation with Nd:YAG is discussed and the steady state as well as time dependent solution of the four level rate equation is analyzed. A two level rate equation model is introduced to explain the saturation behavior of an optical absorber. A saturable absorber (QS) for passive q-switching is introduced. The dynamics of the pulse generation, like repetition rate, pulse width and peak power are determined. The experiment consists of the laser diode pumped Nd:YAG - laser as basic version with an additional passive q-switch (Cr:YAG) crystal. The time dependent signals are displayed and evaluated using an optional oscilloscope. Beside the generation of short pulses, the behavior of the Nd:YAG laser can also be the subject of additional investigations, like measuring the threshold, slope efficiency and so on. By using the optional Pockels cell (AQ) including the high voltage driver (QD), active q-switch can be performed and explored.