The period of a laser, specifically pulsed lasers, is the time from the start of one pulse to the start of the next pulse.
Understanding the period of a laser involves examining the timing of the laser's light emission. Lasers can operate in two primary modes: continuous wave (CW) and pulsed. The period is a term that primarily applies to pulsed lasers, as CW lasers emit a steady beam.
Pulsed Lasers and the Concept of Period
For pulsed lasers, the emission of light is not continuous but rather in short bursts, or pulses. The following table clarifies these concepts:
| Term | Definition |
|---|---|
| Period | The time interval between the start of one pulse and the start of the next. |
| Pulse Duration | The length of time a single pulse lasts, often measured at FWHM. |
| Continuous Wave | Steady emission of light. |
Key Differences
- Pulsed Lasers: These emit light in distinct pulses with periods and pulse durations.
- CW Lasers: These emit light continuously, therefore not having a period in the same sense as a pulsed laser.
How it all fits together
The period of a pulsed laser is crucial in various applications, such as:
- Material Processing: The timing between pulses affects the heating and cooling cycles of the target material.
- Spectroscopy: Precise pulse timing allows for studying ultrafast phenomena.
- Telecommunications: High repetition rate lasers enable faster data transmission.
The period and pulse duration of pulsed lasers are key parameters that determine the laser's suitability for different tasks. While the period describes the time between pulses, pulse duration defines the length of each individual pulse. Unlike pulsed lasers, CW lasers do not have periods; they emit light constantly.
