2
37kviews
Write the difference between LED and Laser diode
1 Answer
written 8.5 years ago by | modified 4.9 years ago by |
LED | LASER |
---|---|
LED - Light emitting diode | LASER - Light amplification by stimulated emission of radiation |
It is polychromatic | It is highly monochromatic |
It is not coherent | It is highly coherent |
Spontaneous emission is responsible for it. | Spontaneous emission is responsible for it. |
Not directional | Highly directional |
Poor energy is associated | Highly energetic |
LED’s are small in size, longer life, reliable & require little power. | Laser’s are bigger in size, longer life, less reliable & require more power than LED. |
Generation of photon by spontaneous emission | Generating photon by stimulated emission. |
LED’s produce a divergent & incoherent light beam. | Laser produces a monochromatic & coherent light beam. |
Types of LED (a) surface emitter (b) Edge emitter | Types of LASER (a) semiconductor Laser (b) Gas Laser |
Their response is fast. | Their response is faster than LED. |
Bandwidth of LED is moderate | Bandwidth of Laser is higher |
Here require drive current is 50 to 100mA | Here require drive current is Threshold current of 5-40mA. |
Feedback is not required in LED. | Proper feedback is essential in LASER to be treated as an optical source. |