Q-switch

Around 60-100 W is required to deflect a 60 W beam and hence the Q-switch has to be cooled.

The Q-switch was placed at the beam waist of the resonator as mentioned before.

The invention of the Q-switch quickly followed the invention of the laser discovered in 1961 and published in 1962 [3].

Also, the appearance of Q-switch and ultra-short pulse technology made the peak power improve greatly, and the efficiency of doubling reached 70-80%.

The general temporal evolution of the Q-switch is sketched in Fig. 4.2 for the case of an active Q-switch that acts on the internal cavity losses Λ.

We see that the timer/controller contains a 10 Hz laser Q-switch signal repeated each 100 ms (the Q-switch pulse width is 100 μs, and the lasar pulse with is 10 ns).

A variety of methods are available to Q-switch a fiber laser. Most of them are adaptations of those used to Q-switch bulk lasers.

The ability to Q-switch this laser results in fast, intense pulses of red light that cannot be generated by other means.

In order to Q-switch an unpolarized laser system, such as Nd:YAG, the lower of the efficiency factors of a longitudinal device determines the extinction ratio of the device.