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Write the difference between LED and Laser diode
1 Answer
| written 9.5 years ago by | modified 5.9 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. |