Introduction of Helium-Neon Laser:
The first gas laser is Helium-Neon Laser was developed by Ali Javan and his co-workers in 1961. The first He-Ne Laser at 1.15Ξm emitted infrared.
Definition of Helium-Neon Laser:
It is a type of gas laser in which a combination of helium and neon gas is utilized as the gain medium is called Helium-Neon Laser. This is also known as He-Ne Laser.
What is a Gas Laser?
The gas laser is a type of Laser in which a combination of gas is utilized like the laser medium or active medium. In lasers, the gas lasers are most widely used. The range of gas lasers is from low-power helium-neon lasers to very powerful lasers that as carbon dioxide lasers. In college laboratories, the Helium-Neon is used while in Industrial applications carbon-dioxide lasers are used. In gas lasers, the advantage is that He-Ne lasers are above solid-state lasers and are less prone to damage by heating over due to this reason run continuously.
What is a Helium-Neon Laser?
It is an active medium that consists of two gases and these gases do not interact with a molecule. Normally, at room temperature, the ruby laser will emit only short bursts of laser light, every laser pulse is taken behind a flash of pumping light. The best laser is one that emits light continuously or consistently. Hence such a type of laser is known as a Continuous Wave (CW) laser.
This is mostly used in gas lasers. It includes a lot of scientific and industrial uses that are utilized in laboratory demonstrations of optics. In addition, the optical pumping method is not used rather in the electrical pumping method. In He-Ne gas the excitation of the electron in an active medium is gained by passing the electric current across the gas. Moreover, this operates at the wavelength of about 632.8 nm in the visible spectrum of the red portion.
Construction of Helium-Neon Laser:
This consists of three important components that are:
- Pump Source or High voltage power supply
- Gain Medium or Discharge glass tube or Laser glass tube
- Resonating Cavity
Pump Source or High Voltage Power Supply:
 |
| Construction of He-Ne Laser |
Gain Medium or Discharge Glass Tube or Laser Glass Tube:
The gain medium is made up of a mixture of neon and helium gas with low pressure contained in a glass tube. When we see their partial pressure means helium is 1mbar while neon is 0.1mbar. This is mostly made of helium gas. To attain the population inversion we require to primarily excite the helium atoms with lower energy state electrons.
The neon has active centers and also has the energy levels are high that are suitable for laser transitions. And for exciting the neon atoms the helium atoms help this. Anode and cathode-like electrodes are passed in the glass tube to transfer the electric current across the gas mixture. For this, it is attached to a DC power supply.
Resonating Cavity:
Now in this case the glass tube is located in between the two parallel mirrors. The mirrors are optically or silvered coated. Silvered is different in each mirror. The partially silvered left side of the mirror is called the output coupler, on the other hand fully silvered right side mirror is called a Fully refllecting or high reflector mirror.
One of the points in between them is that a fully silvered mirror will also fully reflect the light on the other hand a partially silvered mirror will reflect most of the light part yet enable some of the light part to generate the laser beam.
Working of Helium-Neon Laser:
During that time the current flows across the gas, and some of the energy of the energetic electrons transfers to the helium atoms. So the coming update is that in the ground state, the helium atom gains enough energy and bounces to the excited states of energy 20.16 and 2³s level of energy 19.81 eV which is near approximately to the energy of the metastable states of Neon. Later the He atoms convey their energy to the Ne atoms that are in the ground state and then in the metastable states it excites 3s and 2s and in the ground state, the helium atoms come down. This procedure is repeated so it is known as resonant energy transfer mode.
Working diagram:
As for neon atoms, the 3s and 2s are metastable states, due to this gaining or attaining population inversion. Later some period, in neon atoms the metastable states of electrons will spontaneously fall into the lower energy states that is the next states by which photons are released. It is known as Spontaneous emission. Different photons are emitted spontaneously and validated in stimulated emission and generate coherent radiation.
Moreover, in neon atoms, the transition from upper 3s to 2p level produces the radiation of the wavelength 3.39ðm, and 2s to 2p produces a wavelength of 6328A ͦ. Besides transition from the 2s to 2p generates a wavelength of 1.15 ðm. For studying the Synchronous Counter with complete information is.
Because waves with wavelengths 3.39ðm and 1.15ðm are dull as they are occupied by quartz glass tubes we obtain only light with the weight of about 6328A ͦ. The atom's level from 2p to 1s comes down spontaneously and in the ground state, it comes back from the 1s state by the generation of the de-excitation with the help of the collision. Hence, in the Helium-Neon tube, the two ends are at Brewster's angle due to this cutting the unpolarized laser light at perpendicular components and we obtain wavelength 6328A ͦ of polarized light as output.
Application of Helium-Neon Laser:
- It is used in Industries.
- These types of lasers are used in scientific instruments.
- And, is also used in laboratories like in colleges or universities, etc.
Advantages of the Helium-Neon Laser:
- This is working or operating without any of the damage at any of the high temperatures.
- Its price is low.
- It also has high stability.
- The helium-Neon laser emits a visible portion of the laser light of the spectrum.
Disadvantages of the Helium-Neon Laser:
- This laser is limited to low-power tasks.
- Also, has a low gain.
- And low efficiency.
Conclusion of Helium-Neon Laser:
At the time when we concluded the helium-neon laser then according to the scientific research, Measn that in the Labs it is generally used for holography, interferometry, and spectroscopy. For these applications their coherence length is long and stable output power ideally makes them.
According to the Industry, this laser is used in industrial applications like, positioning, barcode scanning, and also alignment. So, this is our final result about this laser.
Most Frequently Asked Questions:
Q: Are you the efficiency of the Helium-Neon Laser?
Yes, I have known the efficiency of this laser. Commercially this is obtainable for about a few mW of 632.8 nm light with the width of the beam of some of the millimeters in the total efficiency of about is nearly 0.1%. When 1watt of the input power in supply the power is 1mW laser light is generated.
Q: When we compare the similarities then which is common in this laser?
Neon has a valence shell of 8 electrons, that is completely filled like helium which also has complete valence shells in similar groups.
Q: Helium is metal or non-metal what is your answer?
Helium is a non-metal gas. While the other non-metal gases involve like as chlorine, hydrogen, fluorine, and others of all eighteen noble gas groups.
Q: Does helium make the bond with Neon or not?
Two electrons in the first orbital of the Helium, and the other of Neon has its first orbital has the two electrons and in the second orbital, the eight electrons are present. It is almost full and carries a maximum number of electrons. Chemically this is not reactive. This is why both do not form a bond with some other of the atoms.
0 comments:
Post a Comment