Time : Mar 20 2015Source :未知 Author : analogtechnologies Click :
Semiconductor laser is also known as laser diode, which uses semiconductor materials as laser’s operation materials. When comparing with other lasers, laser diode has incomparable performances, such as low driving voltage, high efficiency and safe incentive mode, so that it can be widely used for long-distance communication, digital signal storage and recovery, laser range holographic application, etc. Semiconductor laser has strict demands on working conditions and it is much affected by the operating temperature and the driving current. Driving circuit with constant current output has very important practical value for the normal work of semiconductor laser.
The basic operational principle of the semiconductor laser:
Through the metal contact, the forward bias is putted on the PN junction, there is small number of electron and the hole in the operation area and radiation is less than the absorption, so at this moment, the laser can only produce spontaneous radiation and ordinary fluorescent will come out. With the gradually increasing of current, the number of electron and hole will become lager and then the ordinary fluorescent will become brighter. When the injection is increased to gain that can be enough to compensate the loss, it will produce the oscillation of sharp spectral line and clear pattern and then the real laser light will come out.
