What Causes the Difference in Spectral Lines Between Neon Gas and a Helium-Neon Laser?
Understanding Spectral Lines
When we talk about spectral lines, we are referring to the specific wavelengths of light that are emitted or absorbed by an object, such as a gas or a laser. These spectral lines are a result of electron transitions within the atoms of the material.
Neon Gas Tube Emission Spectrum
A glowing tube of neon gas contains a high number of spectral lines in its emission spectrum. This is because neon gas has a more complex electron structure compared to helium-neon gas in a laser.
Electron Transitions in Neon Gas
Neon gas atoms have a larger number of possible electron transitions between energy levels. This leads to the production of a greater variety of spectral lines in the emitted light from the neon gas tube.
Helium-Neon Laser Emission
On the other hand, a helium-neon laser is designed to emit light that is highly monochromatic. This means that the laser produces a single spectral line, as it amplifies a specific electron transition to dominate the output.
Conclusion
In summary, the difference in spectral lines between a glowing neon gas tube and a helium-neon laser is primarily due to the complexity of electron transitions in the gas atoms. The neon gas tube has a greater number of spectral lines in its emission spectrum, while the helium-neon laser emits highly monochromatic light with only one dominant spectral line.