Predict the most compact size, high efficiency laser, and describe its construction and working
Answers
Explanation:
Construction of Laser DiodeA laser diode is made of two semiconductor layers viz: P-type and N-type semiconductor. These semiconductors are made of Gallium arsenide and they are doped with Selenium, Aluminium, or Silicon.The construction of laser diodes is similar to LED, the only difference is that an active layer is made between these two semiconductors. This active layer often consists of a Quantum well and is made of an intrinsic semiconductor (intrinsic semiconductor means undoped or pure or natural semiconductor).A depletion layer is between the two semiconductors because by applying a voltage to the diode, the electron-hole combination occurs.The front is completely polished; this surface acts as a reflecting surface or a mirror while the side view is partially polished which acts as a partially reflecting surface.The front face is attached with metal contacts to allow biassing in the semiconductor. Biasing means supplying power to the diode.Laser diodes provide a light of the same frequency.Now, let’s talk about its working:Working Principle of a Laser DiodeA laser diode works on the principle of stimulated emission and so emissions occur in three types:Stimulated absorptionStimulated emissionSpontaneous emissionGenerally, an electron while migrating to the lower energy level releases energy equal to the gap between them and chances are they come back after absorbing energy.However, a laser diode works on stimulated emission