HE NE LASER PRESENTATION

BIJOY DEY

1. NAME – BIJOY DEY STUDENT CODE – BWU/BTA/21/117 DEPARTMENT – CSE (AI & ML) SECTION – B SUBJECT - PHYSICS TOPIC – HE NE LASER UNIVERSITY – BRAINWARE UNIVERSITY

2. INTRODUCTION A Helium-Neon laser, usually called a He-Ne laser, is a type of small gas laser . He-Ne lasers have many industrial and scientific uses , and are often used in laboratory demonstrations of optics. He-Ne laser is a four-level laser. Its usual operation wavelength is 632.8 nm, in the red portion of the visible spectrum. It operates in continuous working(CW) mode. The Helium-Neon laser was the first continuous laser.

3. CONSTRUCTION OF HE NE LASER Long discharge tube. Length 50 cm and diameter 1cm. Mixture of He & Ne in 10:1 . Left side is fully silvered mirror and right side is partially silvered mirror. It also contains radio-frequency generator.

4. WORKING OF HE NE LASER In He-Ne laser, we use high voltage D.C as the pump-source. A high voltage D.C produces energetic electrons, that travels through the gas mixture. The energetic electrons collide with and excite the He and Ne atoms to metastable states 20.61 ev and 20.66 ev respectively above their ground states. The He atom excites the ne atom by collision to its metastable state. It means He helps in achieving a population inversion in the Ne atoms. When a excited Ne atom passes spontaneously from the metastable state at 20.66 ev to the state at 18.70 ev , it emits a 6328 Angstrom photon. This photon moves back and forth between two reflecting ends of the tube and stimulates all the excited atoms. Finally , we get a laser beam .

5. ENERGY LEVEL DIAGRAM OF HE NE LASER

6. APPLICATIONS OF HE NE LASER The Narrow red beam of He-Ne laser is used in supermarkets to read bar codes. The He-Ne Laser is used in Holography in producing the 3D images of objects. He-Ne lasers have many industrial and scientific uses, and are often used in laboratory demonstration of optics.

7. ADVANTAGE OF HELIUM NEON LASER HELIUM NEON LESAR EMITS LASER LIGHT IN THE VISIBLE PORTION OF THE SPECTRUM. HIGH STABILITY LOW COST OPERATES WITHOUT DAMAGE AT HIGHER TEMPERATURES.

8. DISADVANTAGE OF HE NE LASER Low efficiency Low gain system Helium-neon laser are limited to low power tasks.

9. THANK YOU