Advantages of He-Ne Laser | disadvantages of He-Ne Laser
This page covers advantages and disadvantages of He-Ne Laser. It mentions He-Ne Laser advantages or benefits and He-Ne Laser disadvantages or drawbacks.
What is He-Ne Laser?
• It is one of the most common gas laser type used for low power operation (from 0.0005 to 0.05 Watts). It operates in high voltage and low current (mA) glow discharge.
• It is widely used for LOS (Line of Communication), recording or play back of holograms etc.
• Active medium is mixture of He (i.e. Helium) and Ne (i.e. Neon) gases filled in quartz tube. Here helium (about 85%) is major constituent of the gas mixture but neon component acts as actual lasing medium.
• Its working operation is similar to other gas laser types except cooling arrangement.
• During pumping process, electrical discharge through gas mixture is initiated by high voltage pulse with
current strength of about 10 to 20 mA.
• The ultimate lasing comes from deexcitation of carriers between energy levels (e.g. 3s to 2p) of Ne atoms. He atoms are used as excitation energy provider for Ne atoms only.
• The He-Ne laser output is at wavelength of about 633 nm. He-Ne lasers provide output at other wavelengths such as 543 nm, 594 nm, 612 nm and 1523 nm.
Benefits or advantages of He-Ne Laser
Following are the benefits or advantages of He-Ne Laser:
➨They are small and compact.
➨They offer best inherent beam quality of any laser which virtually pure single transverse mode beam (M2 < 1.05).
➨They have longer life, usually 50,000 hours or more.
➨They generate relatively little heat. Moreover they are convection cooled easily in OEM packages.
➨They have relatively low acquisition and operating cost.
➨Construction of He-Ne laser is very simple.
➨It has very good coherence property.
➨It provides inherent safety.
Drawbacks or disadvantages of He-Ne Laser
Following are the drawbacks or disadvantages of He-Ne Laser:
➨Its output power is lower.
➨It is a low gain device.
➨In order to have operation at single wavelength, the other two wavelengths are required to be suppressed. This requires use of special techniques and extraordinary skills. This increases cost of the device.
➨It requires high voltage for its operation.
➨Escaping of gas from laser plasma is considered to its drawback.