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Discover the Science of Light Therapy; Part 1: Laser vs. LED: What's the Difference?

Have you ever thought about trying light therapy for pain relief, skin care, or anti-aging? Or maybe you're interested in biohacking and improving your mobility. If so, you're in the right place.

This three-part series takes an in-depth look at the benefits and effectiveness of various light therapies. We’ll explore the crucial differences between laser light and LED light, unpack the science behind light therapy, and examine the various ways that laser and LED light therapy can help enhance your health.

No matter your health or wellness goals, this comprehensive resource will provide the insights you need to select the ideal light therapy for you.

Get ready to learn more about how light therapy can improve your life!

Woman receiving deep tissue laser on her shoulder

Part 1: Laser vs. LED Light: What's the Difference?

The word "laser" is actually an acronym for


Amplification by


Emission of


The same is true for "LED", which stands for




Two key differences between laser and LED light are related to the organization, alignment, and range of the light waves.

Lasers and LED lights are both used in photobiomodulation therapy. However, there are some key differences in their properties and mechanisms of action that make them different treatment options. Let’s go over a few of the basic terms you will need to know to better understand how light therapy works.

Colors of light wavelengths and their nanometers.
Photo Source: Science Learning Hub | Pokapū Akoranga Pūtaiao | University of Waikato |

Light Therapy Wavelengths and Nanometers

You know how when you throw a stone into a pond, it creates ripples that move out from where the stone landed? Those ripples are like light waves. And just like how those ripples have a certain distance from one to the next, so do light waves. That distance from one wave to the next is what we call a "wavelength."

Now, let's think about different kinds of waves. Imagine a calm day at the beach where the waves are slow and far apart. These are like red light waves, which have long wavelengths.

On the other hand, imagine a stormy day at the beach where the waves are fast and close together. These are like blue or violet light waves, which have short wavelengths.

So, when we talk about the color of light, we're really talking about its wavelength, or how far apart its waves are. Each color of light has its own range of wavelengths. For example, red light has a longer wavelength than blue light.

Now, what's a nanometer? Well, it's just a really, really tiny unit of length that scientists use to measure these wavelengths. It's so small that you'd need a super powerful microscope to see it. When we say that red light has a wavelength of around 700 nanometers, it means that the distance from one wave of red light to the next is 700 nanometers.

So, in simple terms, when we talk about the wavelength of light, we're just talking about how far apart its waves are, like the distance between ripples in a pond or waves at the beach. And different colors of light have different distances, or wavelengths, which is why they look different to our eyes.

Examples of coherent and non coherent wavelengths

Coherent vs. Non-Coherent

Coherence refers to the alignment and organization of light waves. Coherent light waves are in phase, meaning the peaks and troughs of the waves align perfectly. This coherence allows for focused and highly organized light emission. Laser light is a highly coherent light source.

Where coherent light waves are in phase, non-coherent light waves are not.

Non-coherent light waves have varying wavelengths, directions, and phases. Non-coherent light sources, like LEDs, emit light that is less organized and less focused.

Laser Light Therapy Benefits-

Deep Focused Treatment with Increased Intensity

Because of its coherence, laser light can penetrate more deeply into tissues, allowing for a more focused treatment. Coherent light can deliver higher intensity to a specific area compared to non-coherent light. This could potentially lead to greater therapeutic effects.

LED Light Therapy Benefits-

Safe, Broad Coverage, and Cost Effective

Non-coherent light is generally safer to use than laser light because it's less concentrated and doesn't pose the same risk of accidental eye damage. When dealing with conditions that affect a wider area of the body, such as wounds, large scars, or widespread dermatological conditions, LED lights can offer practical advantages. The larger treatment area coverage allows for comprehensive treatment, ensuring that the entire affected area receives the therapeutic benefits of the light therapy. LED light therapy is commonly used for acne treatment, anti-aging, and wound healing. Of course, it can also benefit musculoskeletal issues such as muscle pain, joint inflammation, and sports injuries.

And finally, LED devices are typically less expensive than laser devices, making them a more accessible option for many people.

Examples of monochromatic and polychromatic wavelengths

Monochromatic vs. Polychromatic

Monochromatic light consists of a single wavelength or color. It emits light at a specific wavelength, typically within a narrow range. Laser light is typically monochromatic, as it emits light at a single wavelength.

Polychromatic Light: Polychromatic light consists of a range of wavelengths or colors. It emits light across a broader spectrum, encompassing multiple wavelengths. LEDs are examples of polychromatic light sources, as they can emit light across a range of wavelengths.

Laser Light Therapy Benefits -

Precise Targeting

Monochromatic light waves have a specific wavelength or color, allowing for precise targeting of tissues or specific chromophores (light-absorbing molecules) within the body, such as hemoglobin or melanin. This allows for increased absorption of light energy by the target tissues, leading to more efficient photobiomodulation effects.

LED Light Therapy Benefits-

Broad Spectrum

LED light therapy can utilize various wavelengths or colors of light, allowing for a broad spectrum of treatment options. Different wavelengths have specific effects on cells and tissues, enabling healthcare professionals to tailor the therapy to the specific needs of the individual and the condition being treated.

Examples of collimated and non collimated light

Collimated vs. Non-Collimated

Laser light is highly collimated, meaning it remains tightly focused and travels in a straight line without significant spreading. This property allows laser light to penetrate deeper into tissues. In contrast, LED light is non-collimated and tends to disperse over a wider area, resulting in shallower tissue penetration.

Laser Light Therapy Benefits -

Deeper Penetration

This property allows laser light to penetrate deeper into tissues. Certain wavelengths of monochromatic light can penetrate deeper into tissues. This property is particularly advantageous when treating musculoskeletal issues or deeper-seated conditions, as the light can reach target tissues at greater depths.

LED Light Therapy Benefits -

Efficiency + Consistency

The ability to treat a larger area at once can reduce the overall treatment time required. It allows for more coverage in a shorter amount of time, which can be beneficial for the client by enhancing efficiency and satisfaction by minimizing the duration of each treatment session. Treating a larger area ensures more consistent exposure to light therapy across the targeted region. This can help maintain a more uniform and reliable distribution of light energy, potentially leading to more predictable treatment outcomes.

But wait! Aren’t coherent and non-coherent the same as collimated and non-collimated?

While they are related concepts, they have different meanings in the context of light.

First, let's tackle "coherent" and "non-coherent" light. This is all about how the light waves line up with each other. In coherent light, the waves all match up perfectly, like dancers doing a choreographed routine. Non-coherent light is the opposite. The waves don't match up and are more like a chaotic dance floor with everyone doing their own thing.

Now, let's talk about "collimated" and "non-collimated" light. This is about where the light goes. Collimated light is like a spotlight that stays focused and goes straight ahead without spreading out. Non-collimated light is more like a regular light bulb that lights up a whole room, with the light spreading out in all directions.

So, in short, "coherent" and "non-coherent" are about how the light waves line up, and "collimated" and "non-collimated" are about where the light goes. They're related, but they're not the same thing.

Woman getting a laser session on her knee

Power and Intensity

The amount of power used in light therapies like laser and LED plays a crucial role in their effectiveness and application.

Think of power in this context like the intensity or strength of the light. A high-powered light, like a laser, is very intense. It can deliver a lot of energy to a specific area in a short amount of time, which can be useful for penetrating deeper into the body's tissues and providing a concentrated dose of therapy to a specific area.

On the other hand, LED light therapy typically uses less power. It's not as intense as laser light, but it can cover a larger area. This makes it more suitable for treating larger regions of the body, or for conditions that affect the skin and the immediately underlying tissues.

Think of it like a spotlight (laser therapy) versus a light bulb (LED therapy). A spotlight is more powerful and focused—it can light up something far away. But it only lights up a small spot. On the other hand, a light bulb is less powerful, but it spreads its light all around the room.

So, laser therapy uses more power and is very focused. It's great for targeting a specific, small area. LED therapy uses less power and spreads the light out more. It's great for covering larger areas, but it's not as intense as laser therapy.

Laser Light Therapy Benefits -

Deeper Biological Change

This increased power and intensity may allow for deeper tissue penetration, resulting in significant biological effects. Because of its coherent nature and higher power density, laser light allows for deeper tissue penetration and interacts more strongly with tissues. The interaction triggers photochemical and photophysical responses in the cells, leading to various cellular effects.

LED Light Therapy Benefits -

Safe + Comfortable

With its lower power and intensity, LED light therapy is considered safe for most individuals when used appropriately. It is non-invasive and non-thermal, meaning it does not produce significant heat or damage to the tissues. The broader coverage reduces the need for multiple passes or repeated applications, minimizing potential discomfort or skin irritation that may arise from prolonged exposure or repetitive treatments.

Wrapping It Up

Hopefully this article has helped you understand some of the terms, principles, differences, and similarities between laser light and LED light. We will build on this information next week when we use these concepts to talk about photobiomodulation (PBM) and how it works in the deeper cells of the body. We are excited to show you how PBM uses light as a therapeutic source for good health and wellness.

Picking between different types of light for treatment—like coherent (organized waves) or non-coherent (unorganized waves), and monochromatic (one color) or polychromatic (many colors)—depends on what you're trying to achieve. It's like choosing the right tool for the job. The best choice depends on what kind of treatment you need, what changes you want to make in your body's tissues, and what health issue you're dealing with.

If you are interested in trying Deep Tissue Laser or LED Light Therapy, give us a call at (804) 559-7990. We would be happy to answer and questions you may have or assist you in scheduling your first visit.

Collage of service pictures from Proactive


The visible spectrum. (2023). Retrieved 16 May 2023, from

Join us next week for Part 2: The Science Behind Phototherapy


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