Use is different in different place, not that kind of bad follow-up: using laser and laser diode for answer: laser generally used in medical, military, belongs to the main characteristics of high-tech product diode is unidirectional conductivity, which is under the action of forward voltage, conduction resistance is small; In reverse voltage, the conduction resistance is great or infinite. Because diodes have these characteristics, they are often used in rectifying circuits.
The voltage stabilizing principle of the diode is: the voltage of the voltage stabilizer is basically unchanged after the voltage breakdown. After the rectifier diode reverse breakdown is damaged. In this way, when the voltage regulator tube access circuit, if the power supply voltage fluctuations, or other causes circuit, the voltage changes at various points in the load on both ends of the voltage will be basic remain unchanged. Zener diode voltage regulator or as a benchmark in the series circuit voltage rectifier diode and zener diodes are p-n semiconductor devices. The difference is rectifier diode with unidirectional conductivity. Zener diode is to use the reverse characteristic. Reverse connection in the circuit.