The most widely used semiconductor light sources are Light Emitting Diode (LEDs) and Lasers. Among these light sources, lasers have gained more importance due its directional properties high energy density.Laser is originated from light amplification by stimulated Emission of Radiation. The Laser is a source of highly directional, monochromatic, coherent light and finds many applications in a medical field, industries, optical communication systems, Entertainment electronics etc.There are many devices used to generate laser. Among these devices, laser di¬odes are commonly used due to its iight weight, small size, and low power consumption and also due to high efficiency to produce light and cheap rate. Laser diodes are the diodes which emit laser. When a devices called LASER DIODE, this generally refers to the combination of semiconductor chip that does actual lasing along with a monitor photo diode chip housed in a package that look like a metal can transistor with a window in the top.