Q-switch

English

Etymology

The "Q" stands for the quality factor of the resonator on the lasar.

Noun

Q-switch (countable and uncountable, plural Q-switches)

1. A device that causes Q-switching.
   • 2003, W. M. Steen, Kenneth Watkins, Laser Material Processing, page 29:

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

   • 2009, Soviet Laser Physics - Volume 19, page 1404:

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

   • 2014, Detlev Ristau, Laser-Induced Damage in Optical Materials, page 3:

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

2. The process of Q-switching.
   • 2012, Jianquan Yao, Yuyue Wang, Nonlinear Optics and Solid-State Lasers:

     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%.

   • 2014, Marc Eichhorn, Laser Physics: From Principles to Practical Work in the Lab, page 75:

     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.

   • 2018, Huabei Jiang, Photoacoustic Tomography, page 109:

     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).

Verb

Q-switch (third-person singular simple present Q-switches, present participle Q-switching, simple past and past participle Q-switched)

1. To use a Q-switch on (a laser).
   • 2001, Michel J.F. Digonnet, Rare-Earth-Doped Fiber Lasers and Amplifiers:

     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.

   • 2011, Mark Csele -, Fundamentals of Light Sources and Lasers, page 295:

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

   • 2013, Walter Koechner -, Solid-State Laser Engineering, page 505:

     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.