DVD Player Laser Wavelength Explained
DVD players use a laser to read data from the optical disc. The wavelength of this laser determines the precision with which the data pits on the disc can be read.
The standard laser used in most DVD players operates in the red light spectrum. Its specific wavelength is crucial for compatibility and performance.
Commonly, the wavelength of the laser found in a DVD player is approximately $650$ nanometers (nm).
Comparing this to the options provided:
- 820 nm (typically used in CD players)
- 540 nm (typically green light)
- 780 nm (typically infrared light, used in some older technologies)
- $650$ nm (standard for DVD players)
Therefore, the correct wavelength for the laser used in a DVD player is $650$ nm.
Similar Questions
What is a DISADVANTAGE of LED lights over LASER lights?
Important Questions from Laser
In a LASER device the instantaneous populations of energy $E_1$ and $E_2$ (figure below) to be $n_1$ and $n_2$ respectively. At thermal equilibrium the relative population is given by $n_2 = n_1e^{-h\nu_{12}/KT}$
The condition for population inversion when stimulated emission dominates is given by
The following are correct about a semiconductor LASER :
1. It requires population inversion
2. It has shorter lifetime than LED
3. It demonstrates spontaneous emission phenomenon
4. It generates monochromatic incoherent light.Find out the correct answer :
In comparison to LED, LASER has
1. high emission frequency
2. no tuning arrangement
3. narrow spectral bandwidth
4. provision for confinementWhich of the following conditions is applicable in semiconductor LASERs ?
Which of the following statements are incorrect in case of semiconductor LASERs ?
(a) Stimulated emission rate dominates the spontaneous emission with increase in the value of energy of radiation per unit volume per unit frequency.
(b) Stimulated emission rate dominates the absorption rate of the charge carriers in the ground state are higher than the excited state.
(c) LASERs have a longer life-line than LEDs.
(d) LASER diodes are more temperature sensitive than LEDs.
Options :
