Laser diode is also called semiconductor laser, usually referred to as LD. Next, let's look at the performance characteristics and applications of laser diode.
Because it can produce light with exactly the same wavelength and phase, high coherence is its biggest characteristic.
The light generated by the injection current is amplified back and forth between the two lenses until the laser oscillates. In short, a laser diode can also be said to be a light-emitting LED that amplifies light through a mirror.
As component materials, compound semiconductors such as AlGaAs, InGaAlP, InGaN, ZnO, etc. are not suitable for laser diodes because the Si transition probability (the probability of current converting into light) used by LSI, TR, Di, etc. is poor.
Performance characteristics and Application
Laser diodes are widely used in various applications, which make full use of the characteristics of straightness, small spot size (um ~), monochromaticity, high optical density and coherence.
Recently, motion sensors, HDD thermal assisted magnetic recording, lighting (projector, headlamp) are also used.
Laser diodes are widely used in low-power optoelectronic devices such as CD-ROM drive on computer, print head in laser printer, bar code scanner, laser ranging, laser medical treatment, optical communication, laser indication, etc., as well as in high-power devices such as stage lighting, laser surgery, laser welding and laser weapons.