What is Laser Diode (LD) and how is it different from Light Emitting Diode (LED)?
A1: Invented in 1963, laser diode is a complex semiconductor device, which emits a coherent beam of light and is becoming the most widely used laser source. Although laser diode and LED are both semiconductors devices with p-n junction and at low operating current they both behave similar (emit non-coherent light). One main difference between the two is the fact that a laser diode has a well-defined threshold current which above it laser (coherent light) emission progresses and output power rises rapidly. What are the similarities and differences comparing HeNe lasers and laser diodes? A2: Although for many years HeNe lasers have been dominated a wide range of laser applications such as bar-code scanners, laser based reading devices, laser didoes have been increasigly replacing HeNe lasers due to one or more of the following reasons: . Due to their high density of atoms within the resonator, laser diodes achieve higher gain than HeNe . Laser diodes have lower over all cost . Laser diod
