Carbon Dioxide Laser: Definition, Principle, Construction and Working, 5 Advantages and Disadvantages.
Carbon Dioxide Laser: Definition, Principle
Definition
In carbon dioxide laser, Co2 gas molecules are used as the active medium and population inversion is achieved by the electrical pumping method.
Principle
The active medium is a gas mixture of CO2, N2 and He. The laser transition takes place between the vibrational states of CO2 molecules.
Energy states of CO2 molecules
Carbon dioxide (Co2) is a symmetric molecule (O=C=O) and it has three modes of vibration:
- Symmetric stretching.
- Bending.
- Antisymmetric stretching is shown in the figure.
Symmetric stretching mode
In this mode of vibration, carbon atoms are at rest and both oxygen atoms vibrate simultaneously along the axis of the molecule departing or approaching the fixed carbon atoms.
Bending mode
In this mode of vibration, oxygen atoms and carbon atoms vibrate perpendicular to the molecular axis.
Asymmetric stretching mode
In this mode of vibration, oxygen atoms and carbon atoms vibrate asymmetrically, i.e., oxygen atoms move in one direction while carbon atoms in the other direction.
