If the time of pulse duration is changed from milliseconds to nanoseconds, how is the laser classified?

When the pulse duration of a laser is changed from milliseconds to nanoseconds, the laser is classified as Q-switched. Q-switching is a technique used to produce short flashes of laser light with high peak power. By reducing the pulse duration to the nanosecond range, the laser is able to achieve a much higher energy output in each pulse compared to longer pulse durations.

The Q-switching process involves temporarily storing energy in the laser medium and then releasing it all at once, resulting in a very short and intense pulse. This high peak power is particularly useful for applications in skin rejuvenation, tattoo removal, and other aesthetic treatments, as well as in scientific and industrial uses where powerful bursts of light are required.

In contrast, continuous wave lasers produce a constant beam of light and do not involve pulsing; solid-state lasers are identified by their gain medium, typically a solid crystal or glass; and diode lasers operate differently, usually employing semiconductor materials. These characteristics set Q-switched lasers apart, particularly when the focus is on rapid, high-energy pulses.