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Therapeutic Lasers and Wavelengths Explained

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Kalon Prensky

20+ Year Laser Specialist, Founder of Discover Lasers LLC &

There are 3 main categories that people use to compare therapeutic laser systems: 

• Power density (measured in milliwatts [mW] for class 1-3b and watts [W] for class 4 laser systems) 

• Wavelength (measured in nanometers [nm]) or Wavelengths (when multiple wave forms are used in the same laser)

• Pulsing, which includes: Pulsed laser (PL), continuous wave (CW) laser and super pulsing technology (SP). 

Some lasers are super pulsed, some pulsing only, some continuous wave only and some combine both pulsed and continuous wave aka CW). CW provides the most amount of power to the cells faster than pulsed, depending upon the duty cycle. Pulsed is often used to help keep the devices from overheating. A pulse at 50% duty cycle means that it will produce twice as long to produce the same amount of power delivery vs CW.

These are the primary variables that determine the quality of laser light (measured in Joules for power and Hz for pulsing frequency) administered to the treatment area. 


A laser’s ability to successfully treat a wide variety of symptoms and conditions is mostly based on power output at an appropriate wavelength, with some potentially added benefit from pulsing with Hz frequencies. 

Many laser therapy protocols call for a specific amount of Joules per cm squared (J/cm2). Pulsed laser therapy increases the time it takes to build up an energy dosage compared with continuous wave lasers and CW light therapy devices such a LZR. The addition of pulsing can make up for the lower dosage and the Hz frequency, which causes the pulsing, often lends additional therapeutic benefits. 

A common solution is to set the laser on pulsing and increase the treatment time to achieve the same dosage. 

Most of the scientific research is focused on dosage, which is the total energy put into the treatment area as measure by J/cm2. There is less emphasis in the research on using unusual wavelengths and pulsing frequencies but there is still some evidence that combining cold laser with Hz frequency is also helpful for achieving maximum benefits in some situations. For example: The earth emits an electromagnetic frequency of 8Hz. It has been determined over many decades of research that prominent and successful healers also emit an electromagnetic frequency of 8Hz. Martial artists, Saints, Sages and Healers have known for  thousands of years that developing a grounded connection to the earth is good for health, healing and balancing. 

Choosing a wavelength: 

Many people are confused and concerned about finding and choosing the right wavelength. This guide will help you to more confidently wade through the noise, hype and claims and make a more educated decision. To begin with, it is important to differentiate between the often-confused Near Infrared or NIR and Far Infrared or FAR, which are totally different. NIR or IR as it is most commonly referred to is what’s used in cold lasers and warm lasers. FAR is used in saunas and heat lamps. While they are both beneficial for health, they do different things. Only cold laser therapy and Class 4 Laser Therapy delivers photons directly to cells for conversion to ATP in the Mitochondria of the cells. A defining accomplishment never before achieved by any other therapy or technology. 

The Near Infrared (NIR) category of wavelengths is at the far end of the Infrared Laser Spectrum. It is quite popular because it is longer and penetrates deeper than all other wavelengths, down to the bone and into hard tissues. It ranges from 780nm to 1064nm. The 1064nm & 980nm wavelengths for example are best suited for use with Class 4 lasers. 780nm to 850nm are the ones that are most highly used and promoted in Class II, IIIR and 3B lasers for the simple reason that they work, by maximizing tissue photon absorption. 

The 808nm-810nm wavelength has won preference as a preferred wavelength among many who have used, studied and tested it in both human and animal studies. It has been hypothesized that the 810nm wavelength is the ultimate for activating PhotoBioModulation or PBM for short. Although the 780nm through 850nm also reside within the narrow window optimized for PBM and are widely used in laser therapy devices. The 905nm wavelength is most commonly used for super pulsed lasers. It’s a longer wavelength, and touted to offer deep penetration. However, other studies suggest that class 4 lasers that have significantly higher tissue saturation at the targeted depth, which is consistent with ongoing research, will produce superior results faster. It would clearly be a mistake to consider one without the other. Power in Watts or Milliwatts is the number of photons delivered in a unit of time. The energy deposited (Joules), and absorbed by the Mitochondria is the  accumulation of these photons over time (1 Watt = 1 Joule per 1 second). When you start out with more Watts at the surface, more will penetrate to the desired depth.

Mechanisms of phototherapy

The wavelength of the light significantly affects depth of penetration and how it interacts with cells and tissue in the body. Although there is no one right answer, the general consensus is as follows: 

Using different wavelengths allows more flexibility in a treatment. Each wavelength can affect cells in a slightly different way. This provides the option for several different mechanisms to treat the same or multiple issues in a single client with the same device. Two to four wavelengths is ideal depending on how it will be used. 

Infrared diodes in the 800nm range (780nm to 830nm) are best for deep tissue and musculoskeletal work because they are not quickly absorbed by hemoglobin or water and tend to work better for hard tissue issues. 

Many higher-end and more expensive cold lasers and super pulsed lasers offer wavelengths in the 904nm and 905nm range, because they have proven results over many year of successful application. Class IV lasers commonly use the 980nm wavelength. This is the preferred option for rapid pain control. Class 4 lasers, due to significantly more powerful laser diodes, are more expensive than class 1 through 3 lasers. The 980nm wavelength shares some therapeutic characteristics with 780nm to 850nm lasers, however the bulk of the energy is absorbed by water/blood and goes to creating thermal gradients in the H2O that increases circulation and blood flow. The increase in circulation allows the bodies natural healing process to accelerate. Class IV lasers have become popular for high-end, speedy pain control and some doctors prefer the 980nm system due to quicker treatment times and the highest level of pain control. Additionally, 980nm can also serve well in some cases for surgical laser applications such as to cut, cauterize, coagulate, neuter and declawing; when the laser can produce in excess of 20 Watts. 

The flipside to 980nm is that much of the energy converts into heating water in tissue, which is great for laser surgery and rapid pain relief, but less productive for regenerative therapy. Consequently, most class 4 laser manufacturers offer a dual wave laser that combines 980nm with and equal power output from the 808-810nm wavelength. The top brands are now combining 2, 3 or 4 wavelengths into a single 27W, 30W or 45W Triwave, Quad or Dual Wave Laser to increase treatment possibilities from the same laser system. 

Laser emitters in the red laser spectrum of 600nm to 660nm range are recommended for treating, inflammation, root nerve, acupuncture and trigger points. Red light lasers are great for soft tissues and small joints, with shallow penetration up to 1”. They are useful as a guiding light when used in combination with infrared lasers, which are mostly invisible to the human eye. 

The growing consensus in the cold laser industry is that multiple wavelengths are beneficial to effectively treat the widest range of conditions. The type of healing needed will dictate to the laser user which wavelength is preferred. 

For example: Red lasers are great for soft tissue issues, nerves, skin, shallow muscles & the strongest anti-inflammatory effects. Infrared (IR) Lasers, sometimes called Near Infrared (NIR) lasers deliver a significantly longer wavelength, typically down to the bone level and are preferred for hard tissue issues such as bones, tendons, ligaments, spine and large and small joints of the musculoskeletal system. 

Fortunately, protocols that call for treatment of acupoints (acupuncture points) can be treated with nearly all of the therapeutic wavelength lasers because an acupoint is close to the surface of the skin, as revealed by heat and skin resistance sensors. Anything you can do with a needle, you can do with a laser, just faster, easier, more effectively and completely painlessly. Rather than treat 4-12 different points simultaneously, leaving a needle in the points for 20-40 minutes, the laser user treats one point after another for 4 to 60 seconds over each point, depending upon the laser power output. The higher the power output, the faster the treatment. There is much debate as to which wavelength is ultimately the best or superior for acupoints since Infrared, Red and Blue/Violet wavelengths all penetrate deep enough to activate acupuncture points and support energy flow through meridians. However, Infrared wavelengths can simultaneously activate acupoints, meridians, muscular skeletal systems and support PBM.

Laser Power Density Explained 

Much of the misinformation about cold lasers aka low level lasers is related to power levels, exposure time to the laser and how they affect the safety and effectiveness of the end product. Low power laser manufacturers have many ways to justify why their product is the best and safest. However the growing consensus is that power is the single most important factor in determining the overall effectiveness of laser therapy (bio-stimulation) when it comes to fast pain relief. Yet it is important to note that some class 4 lasers, AKA warm lasers may have the capability to burn tissue if used incorrectly. That said, more power is frequently better in a clinical setting because it allows practitioners to give patients higher dosage when it is appropriate, without wasting time. This allows the practitioner to give much greater potential for pain relief and therapeutic benefit in significantly less time. 

Laser Penetration and Saturation Graphic

FDA Laser Classification 

Lasers come in classes 1 through 4. This classification is often highly misunderstood. In reality it is easy to understand. Lower numbers equal a more user-friendly safety factor and the higher the number, the greater the risk is of injury to the eye. 

Class 1 & 2 lasers can be purchased for use at home, typically referred to as over-the-counter (OTC) for use on humans and no license or prescription is needed. These lasers have a maximum power of 5mW continuous per diode. Several manufacturers make higher power lasers that qualify as a class 1 or 2 by pulsing or super pulsing higher powered laser diodes or using only LEDs. For the sake of time and effectiveness, it’s a good idea to avoid inexpensive laser pens and pointers as they simply don’t emit enough power to treat a given point or injury in a reasonable amount of time with predictable effectiveness. 

Class 3, IIIR, 3a and 3b

Class 3a lasers are not common or particularly desirable. Class IIIR lasers represent the highest safety classification similar to Class I and are non-significant risk devices, usually given OTC clearance, meaning anyone can buy them without a license or prescription. Class 3b lasers are sometimes considered the gold standard of therapeutic cold lasers. They are designed for practitioners, but can be purchased for use on humans at home with the recommendation of a health care provider. They can be purchased without any restrictions for use on pets and horses. Class 3b lasers are commonly less than 500mW per laser diode continuous output. Several manufacturers have higher power laser devices that use multiple 500mW diodes that have TOTAL power level in the class 4 range, but are safe enough to qualify as a class 3b device because they have less chance of eye damage and no chance of tissue heating damage.

Class 4 lasers

These laser devices offer the most power along with the greatest tissue saturation of photons and the deepest penetration to deeper structures. They typically cost the most and and they pose the highest risk of injury to the eye, thus the requirement for safety glasses and other precautions. They feature one or more laser diodes calibrated with a power output in excess of 500mW. Class 4 lasers typically start at 7000mW (7 Watts) and can range all the way up to 60 Watts without doing damage to the eye or tissues, when used correctly. This danger is easil eliminated with training. However, it is important that practitioners utilize Class 4 lasers in a laser safe room with proper signage and while both patient and practitioner are wearing laser safe goggles or glasses. Class 4 lasers can be sold for home use with a recommendation letter (prescription) from a Physician. They may also be sold for use on animals without any restrictions, however, training is recommended and offered by reputable sellers of Class 4 Lasers.

Laser Wavelength 

The wavelength of a cold laser is important because it determines three things: depth of penetration, absorption of photonic energy and reduction of inflammation. There is a therapeutic window in which energy is best transferred into tissue. Most lasers operate in a therapeutic range from 635nm (Red) to 1080 (NIR). Most common wavelengths are 635, 650, 660, 780, 810, 905, 910, 980 and 1064nm. These wavelengths have advantages and disadvantages as discussed below. 

600nm to 660nm is the red laser wavelength, which is best for shallower treatments up to 1⁄2” and for neurological applications. Commonly used in cosmetic and skin care lasers. Good for treating skin, wrinkles, wounds, burns, acne, small joints, lymphatic tissue, acupoint therapy and other shallow areas. It is also popular for neurological applications and more complex issues because much of the energy is absorbed by the blood flowing throughout the body. This activates and supports healing in different problem areas through a cascade effect. 

800nm to 860nm are the lower Infrared (IR) spectrum with 810nm considered the sweet spot for combining maximum penetration, depth and a positive photo-chemical reaction now called PhotoBioModulation or PBM. European laser specialist such as Dr. Weber and Dr Hamblin promote 810 nm as the optimum wavelength because it is said to produce the maximum interaction with the mitochondria, which is the powerhouse of the cell and responsible for converting the photonic energy from the laser into ATP. 

900nm to 1064nm is the higher IR spectrum, which is very popular in super pulsed lasers and class 4 lasers. 904-910nm being the standard for all super pulsing lasers. 980nm was the first gold standard wavelength used with class 4 laser systems. At 980nm, much of the energy is converted to heat and absorbed by the water/blood in the tissue, which supports blood circulation, reduction of inflammation and rapid pain relief. Because it is less efficient than 810nm at creating photobiomodulation, all the newest Class 4 lasers now combine 980nm with 810nm for use simultaneously to produce superior results. With the delivery of more power a greater tissue saturation is achieved quickly, which results in superior pain relief and regeneration that allows for healing of a wide range of maladies when patients are treated 2-3 times per week for 6-12 treatments. The 1064nm wavelength has become popular over the last few years after practitioners discovered that they could use it in Class 4 lasers to deliver more power and deeper penetration with minimal extra heat to maximize patient comfort and achieve superior results and less time.


Several of the best Class 4 lasers on the market for Practitioners today are those that utilize multiple wavelengths: 810nm, 980nm & 1064nm simultaneously. When all of these wavelengths are combined in a laser, it is called a TriWave laser. The REMY FX45 TriWave is the most affordable high end TriWave Class 4 Laser combining 15 Watts of 810nm, 15 Watts of 980nm and 15 Watts of 1064nm with all German diodes. Most of the high power laser diodes in the the major brands of Class 4 lasers today are made in China these days, and they are quite good. However, the laser diodes that are made in Germany have a reputation for superior performance and longevity.

Other multi wavelength lasers include the REMY Dual & Quad or MEDRAY Dual or Quad. They offer more flexibility in treating a wider range of ailments with a single laser and tend to cost more than single wave lasers, but produce superior results and work for a wider range of issues.

For home laser users and Practitioners who want something less expensive or who prefer a safer high power light therapy device, we recommend the LZR UltraBright, which strikes a perfect balance between power, tissue saturation, speed of treatments, ease and safety of use and cost effectiveness. The LZR UB is perfect for home users who want true optical Continuous Wave (CW) class 4 power without the cost or requirement to wear protective eye glasses. There are 3 power levels of the the LZR UB: LZR UltraBright 20W | 12.5W | 10W. The 20 Watt is the newest, most powerful and fastest performing on the market. Practitioners who lend out or rent light therapy devices for patients to use at home love the LZR UltraBright devices. Click here to learn more about the 3 LZR UltraBright Light Therapy Devices.

20W LZR UltraBright on Face
LZR UltraBright on Dog
LZR Ultrabright-On Shoulder-768x432-1

For Complimentary Concierge Service and Support with a 20 Year Laser Specialist, Call Mr Kalon Prensky at:
808-870-0348 or 800-575-7963 or Continue reading about our fantastic Class 4 Therapy Lasers with the following links: Choose from 10 Models of the REMY or 6 Models of the MEDRAY Class IV Therapy Lasers.

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