A pulsed laser diode is a type of laser that emits light through the use of electric current and semiconductor materials. Laser diodes are similar to Light Emitting Diodes (LEDs), but include additional components to give the laser beam coherence. The extremely fast pulses in these types of lasers can rapidly transmit large amounts of data and can also be beneficial in surgical fields as well as in physics research. Other fields that use the technology include consumer electronics and the defense industry,
Light Amplification by Stimulated Emission of Radiation (LASER) technology differs from other methods of producing light in several ways. Lasers manipulate the electrons inside atoms to fine-tune the release of photons, ultimately producing a highly-focused beam of light energy in a specific wavelength or color. Lasers come in a wide assortment of types, sizes, colors, intensities, and power levels. Laser diodes, also called semiconductor lasers, are among the smallest and least powerful types, and operate by means of electric current rather than the chemical reaction found in much larger variants. A pulsed laser diode, as its name might imply, is a laser diode meant to emit light in quick bursts or pulses rather than a continuous beam.
Consistent with virtually all modern types of diodes, laser diodes are made of semiconductor materials with special electrical properties. Their design and operation is very similar to that of an LED. In the most basic types of both devices, electrons release energy in the form of visible photons as they cross a junction where two different types of semiconductor materials meet. In practice, laser diodes are often more complex, sometimes consisting of multiple layers of different semiconductor material sandwiched together. Laser diodes also include optical components to produce a laser beam appropriate to the diode’s intended use and may be grouped together in an array.
While continuous operation is desirable in many uses of laser technology, pulsed lasers can provide a number of unique benefits. The telecommunications industry, for example, uses laser technology to transmit large amounts of digital information by controlling the rate, timing, and duration of pulses. Depending on how the technology is applied, a pulsed laser diode may emit bursts of light that last just a few trillionths of a second. These ultrafast pulses can also make cosmetic and surgical procedures more efficient because the pulse is too brief to damage surrounding tissues. Pulsed laser diodes are also being explored as a treatment for hair loss.
There are a variety of other possible uses for pulsed laser diode technology. Many consumer electronics devices over the years have used it, as did the laser rangefinder inside the United Kingdom’s Chieftain tank. Physics research may employ a pulsed laser diode directly or even use one or more of them to help drive larger and more powerful lasers.