Pulsed Lasers | previous | next | feedback |
Definition: lasers emitting light in the form of pulses
Pulsed lasers are lasers which emit light not in a continuous mode, but rather in the form of optical pulses. The term is most commonly used for Q-switched lasers emitting nanosecond pulses, but this article gives an overview of a wider range of pulse-generating lasers. Depending on the pulse duration, pulse energy, pulse repetition rate and wavelength required, very different methods for pulse generation and very different types of pulsed lasers are used. The article on pulse generation describes more in detail the technical methods, whereas this article discusses some types of pulsed lasers:
- For nanosecond pulse durations, various types of Q-switched lasers can be used. High pulse energies are achievable with solid-state bulk lasers. For small pulse energies, a microchip laser or a fiber laser can be suitable.
- Nanosecond pulses in the ultraviolet spectral region are generated with excimer lasers.
- For boosting the average power (particularly of high repetition rate pulse trains with moderate pulse energies), high-power fiber amplifiers can be used.
- Pulses with durations in the picosecond or femtosecond domain are usually generated with mode-locked lasers, which may be solid-state bulk lasers, fiber lasers, or semiconductor lasers. For high pulse energies, one uses regenerative amplifiers or cavity-dumped lasers.
- Gain-switched semiconductor lasers are suitable for nanosecond or picosecond pulses with relatively small energy.
- Relatively long pulses can be generated e.g. with laser diodes in quasi-continuous-wave operation.
See also: pulse generation, pulses, lasers, Q-switched lasers, mode-locked lasers, ultrafast lasers, gain switching
