Mechanical Devices

Q-switches have been designed based upon rotational, oscillatory, or translational motion of optical components. These techniques have in common that they inhibit laser action during the pump cycle by either blocking the light path, causing a mirror misalignment, or reducing the reflectivity of one of the resonator mirrors. Near the end of the flashlamp pulse, when maximum energy has been stored in the laser rod, a high Q-condition is established and a Q-switch pulse is emitted from the laser.
Mechanical Q-switches are relatively slow and tend to emit multiple pulses; also, the mechanical wear requires frequent maintenance. Owing to these disadvantages mechanical Q-switches have been replaced by electro-optic or acoustooptic devices.