TMCnet Feature
January 06, 2021

The Pros And Cons Of Hene Laser As Well As Its Alternatives



Helium-Neon lasers, or better known as HeNe lasers, are gas lasers that operate using a mixture of Neon and Helium gases excited by electrical discharges. This is a unique laser because they are cheap to produce and easy to use compared to other types of lasers. This kind of laser has multiple wavelengths that are flexible, atomic transitions that are very stable, and offers confidence when being used. It has gained popularity because of these features, with main fields such as the optical sector taking it up to perform different medical procedures. Its use is not limited to the medical field only but to many research fields as well. The use of the HeNe laser comes with both positive consequences as well as negative consequences. Both effects are discussed below.



The advantages of using HeNe laser technology are:

It has a High Coherence Length

The HeNe laser, just like many other types of lasers, has high coherence strength, which ranges between 20cm to over 100m. several factors determine the coherence strength of the HeNe laser, and these include the cavity mirrors and parameters as well as the etalons incorporated in the design.

It has a Stable Central Wavelength

In the air, the HeNe laser has a very stable central wavelength of about 632.816 nm, which does not fluctuate quickly. However, more sophisticated HeNe lasers require additional stabilization measures because they experience a stable oscillation frequency of less than one MHz. A non-stabilized HeNe laser has a central wavelength that can slightly drift within the range of 1 pm. This is a very slight drift when it is compared to the drifts experienced by other lasers; hence the HeNe laser is very stable.

The HeNe Laser has a High Spectral Purity

The HeNe laser possesses high spectral purity because wavelengths from different waves cannot easily contaminate it. The HeNe laser medium is composed of several emission peaks, but it is possible to direct the HeNe laser to oscillate in one of the several emission bands. When it oscillates in one of the emission bands, other emissions from other bands cannot be detected or interfere with the current HeNe laser. This is a very vital advantage that the HeNe laser has over other types of lasers.

It has an Excellent Alignment and Beam Quality

The HeNe laser has a good beam quality and alignment, making it effective in its applications in different sectors such as the optical field. The HeNe laser is channeled through long gas tubes, making it develop a great Gaussian beam profile, excellent angular and spatial alignment, and good beam quality. Therefore, the laser housing plays a critical role in determining the quality of the beam as well as the alignment when the HeNe laser is being used.

It Harbours Low Costs

The HeNe laser has grown in popularity over the years, and its use in diverse sectors has also grown. Its increasing demand has led to the production and manufacturing of HeNe laser for different uses such as barcode scanning and compact disk uses. These uses have driven the costs of the HeNe laser down, with a laser of about 3mW costing an average of 1000 Euros. This is a low price when the laser’s unique and effective characteristics are that it has.

On the other hand, the use of the HeNe laser has its drawbacks. Some of these disadvantages are discussed below.

HeNe lasers have a Short Life Span

HeNe lasers have relatively short life spans because the helium atoms present in the laser tend to diffuse across the glass tube wall because of their small nature. Even though Helium is critical in regulating the lasing threshold, it gets depleted so fast. The use of HeNe lasers could last up to less than one year because of the loss of helium atoms in the laser system. This issue is considered the most significant drawback of the HeNe laser technology in many industrial applications.

It has a Very Long Warm-up Time

The HeNe laser operation has an estimated warm-up time of ten minutes, as specified by most manufacturers. For small applications where the laser does not have to operate continuously, it might not be a big deal. However, many applications require the laser to run continuously by being turned on and off, making the HeNe laser ineffective. Many companies using this type of laser are forced to purchase and install mechanical shutters that guide laser exposure by making the HeNe laser operate continuously. The continuous operation also contributes to the decrease in its life span.

It Has a Low Power Output

The majority of the HeNe lasers produce a power output of about 30 to 50 mW. This power output range is extremely low compared to other lasers, such as the TEM00, which emits about 100 to 200mW. Other lasers produce larger power outputs than the HeNe laser, making it less effective in many industrial applications.

It is Extremely Large

The HeNe laser machines are very large. For instance, a HeNe laser machine that emits 35 mW of power output is approximately a meter long. This makes it an uphill task transporting, storing, and even buying the HeNe laser units. The majority of HeNe laser units have been confined for use in laboratories and research institutions rather than industries that require efficient machines. This is another considerable downfall of the HeNe lasers, making them not readily acceptable in different industries.

The HeNe Laser Uses High Voltage

Machines often use low voltages when operating in industries. However, the HeNe laser uses exceptionally high voltages during its operation. A typical HeNe laser unit uses voltages above 1500 Volts. These high voltages expose workers and other machines to huge risks, such as severe shock, burns, damage to muscles, as well as even death to people. High voltages can also cause damage to other machines and equipment that operate nearby. It may also result in electrical fires when specific machines’ voltage limits are exceeded far beyond the manufacturer’s specified levels. Therefore, the use of HeNe lasers requires people to take many precautions.

Alternatives of the HeNe Laser

The HeNe laser is a unique type of laser that has revolutionized industrial laser applications. There are very few lasers that can actively replace the exact functions of the HeNe laser globally. One of the renowned lasers that emit lasers in the range of 633 nm is the semiconductor laser. The semiconductor laser produces an output power of about 100mW, lower than the HeNe laser. This alternative laser can actively compete with the HeNe laser because the HeNe laser has serious downfalls that must be addressed before it becomes very effective and efficient in its industrial applications.

In conclusion, the HeNe laser is unique and is being developed to meet the industrial application requirements. It has a lot of advantages in the market, some of which include having a high coherence length, a stable central wavelength, low costs, excellent beam alignment and quality, and high spectral purity. However, the road is not all smooth because it also has its significant drawbacks. The drawbacks include having a short life span, low output power, long warm-up periods, being too bulky, and using high voltage for its operation. These drawbacks have limited the HeNe laser’s use in many industries, giving rise to different alternatives such as the semiconductor laser. Despite all the drawbacks, the HeNe laser remains a unique, top-notch, and intelligent technology in the current market.



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