Table of Contents
What is the basic requirement of He-Ne laser?
The helium-neon laser consists of three essential components: Pump source (high voltage power supply) Gain medium (laser glass tube or discharge glass tube) Resonating cavity.
Why He is used in He-Ne laser?
The role of the Helium gas in He-Ne laser is to increase the efficiency of the lasing process. Two effects make Helium particularly valuable: The direct excitation of Neon gas is inefficient, but the direct excitation of He gas atoms is very efficient.
What is basic requirement of He-Ne laser describe the construction and working of He-Ne laser?
A Helium–Neon laser or He-Ne laser, is a type of gas laser whose gain medium consists of a mixture of 85\% helium and 15\% neon inside of a small electrical discharge. The best-known and most widely used HeNe laser operates at a wavelength of 6328 Ao, in the red part of the visible spectrum.
How many laser transitions take place in He-Ne laser?
This gas laser is a four-level laser that use helium atoms to excite neon atoms. It is the atomic transitions in the neon that produces the laser light. The most commonly used neon transition in these lasers produces red light at 632.8 nm.
How many laser actions take place in He-Ne laser?
The He-Ne laser produces three different wavelengths that are 1.152µm, 3.391 µm and 632.8nm. At the 1st two the infrared photons are released while at the 3rd one i.e. 632.8nm more energetic photon of red color are released because in spectrum at 632.8 approximately red color occurs.
What is the role of He in He-Ne laser explain the working with a suitable energy level diagram?
Working of He-Ne It is a four energy level laser system. The electrons produced from electric discharge collide with He and Ne atom and excite them to the higher energy levels He2 and Ne4 at 20.61 eV and 20.66 eV respectively. Thus, He atoms help to achieve population inversion in Ne atoms.
Why is neon used in lasers?
Helium-neon (He-Ne) lasers are widely used for interferometry because they are inexpensive and provide a continuous, visible output. They operate normally at a wavelength of 633 nm, but modified versions are available with useful outputs at other visible and infrared wavelengths.
Which pumping is used in He-Ne laser?
Which pumping method is used in He-Ne laser? Explanation: Generally, in He-Ne laser, an electric discharge is used to excite the atoms of the active medium. This process is known as Electrical Excitation and is normally used in gas lasers.
Why is Ne laser superior to ruby laser?
Why helium neon laser is better than ruby laser Ruby laser requires high power pumping source, whereas Helium-neon laser requires low power pumping source like electric discharge. Efficiency of helium-neon laser is more than ruby laser. The defects due to crystalline imperfections are also present in the ruby laser.
Which pumping technique is used in He-Ne laser?
Why is helium mixed with neon in He-Ne laser?
The gas mixture is mostly helium, so that helium atoms can be excited. The excited helium atoms collide with neon atoms, exciting some of them to the state that radiates 632.8 nm. Without helium, the neon atoms would be excited mostly to lower excited states, responsible for non-laser lines.
What is the construction of a He-Ne laser?
Construction of He-Ne Lasers The construction of typical He-Ne laser plasma tube can be shown as: The tube where the lasing action takes place consists of a glass envelop with a narrow capillary tube through the center.
What are the disadvantages of He Ne laser?
Disadvantages of He-Ne Laser The weak points of He-Ne laser are It is relatively low power device means its output power is low. He-Ne laser is low gain system/ device. To obtain single wavelength laser light, the other two wavelengths of laser need suppression, which is done by many techniques and devices.
What is the tube diameter of a HeNe laser?
In most HeNe lasers the tube diameter is not larger than a few millimeters. An additional benefit of the small tube diameter is that the emission is restricted to the TEM00 mode; higher order transverse modes cannot oscillate in very narrow tubes.)
Why are visible transitions not used in He-Ne lasers?
Because visible transitions have somewhat lower gain, these lasers generally have lower output efficiencies and are more costly. The 3.39 μm transition has a very high gain, but is prevented from use in an ordinary He-Ne laser (of a different intended wavelength) because the cavity and mirrors are lossy at that wavelength.