The difference between continuous laser and pulsed laser

pulse

    It is a mechanical form such as a wave (electric wave/light wave, etc.) emitted at the same time.

    Laser pulse

    It refers to a light pulse emitted by a pulse-operated laser. Simply put, just like the work of a flashlight, the button is continuously operated when the button is closed, and the "light pulse" is issued when the switch is turned off immediately. It is necessary to work in pulse mode, such as sending signals and reducing heat generation. Laser pulses can be extremely short, such as the "picosecond" level, which means that the pulse time is on the order of picoseconds, and 1 picosecond is equal to one trillionth of a second (10E-12 seconds).

    Continuous laser

    The laser pump source continuously supplies energy and produces a laser output for a long time to obtain a continuous laser. Continuous laser output power is generally low, suitable for occasions requiring laser continuous operation (such as laser communication, laser surgery, etc.)

    Pulsed laser

    The pulse mode of operation refers to the way to work once every interval.

Pulsed lasers have large output power and are suitable for laser marking, cutting, and ranging.

Common pulsed lasers: yttrium aluminum garnet (YAG) lasers, ruby lasers, sapphire lasers, neodymium glass lasers, etc. in solid-state lasers. There are also nitrogen molecular lasers, excimer lasers, and the like.

Continuous lasers, as the name suggests, use laser output to be continuous in time, the output of the pulsed laser is discontinuous, and the shortest commercial speed can be on the order of a few femtoseconds, so pulsed lasers are often used to measure ultra-fast physical processes. However, continuous lasers are also beneficial. After frequency stabilization, a narrow line width can be obtained, which can be used for laser ranging and fine spectrum.

    The peak power difference between the two is very large. The better semiconductor laser in the continuous laser can achieve the hundred W level, and the pulse laser can now achieve the magnitude of TW in the femtosecond. The shorter the pulse width, the less the thermal effect, the fine There are more pulsed lasers in the process.

    Peak power = single pulse energy / pulse width;

    Average power = single pulse energy * repetition frequency.

    The pulse width of the laser is for a pulsed laser or a quasi-continuous laser, which can be understood simply as the duration of one laser pulse per shot or the duration of one laser pulse. The repetition rate is the number of pulses emitted by the laser per second. For example, 10 Hz means that 10 laser pulses are emitted in one second. However, the pulse width of each laser pulse varies from laser to laser, and is nanosecond or subtle or millisecond.