21
Apr
2026
From addressing pigmentation and vascular concerns to improving skin texture, tone and scarring, lasers are now used routinely in clinics around the world.
And yet, it can be incredibly difficult to navigate the complex world of lasers, whether that’s understanding different laser wavelengths, the wide variety of device types or all the unfamiliar terminology that gets thrown around by device manufacturers.
Sometimes, you just want a clear explanation of what a laser is, how it works and what the end result is.
In our Laser 101 blog series, we’ll do exactly that.
This first post focuses on the basics, breaking down how lasers work and introducing the key principles behind laser therapy for the skin.
In the posts that follow, we’ll take a closer look at individual laser types and wavelengths, exploring how each one is used in clinical practice
What does laser stand for?
“Laser” is an acronym that stands for Light Amplification by Stimulated Emission of Radiation.
At its most basic level, a laser produces light. But unlike everyday light sources, such as light bulbs or sunlight, laser light behaves in a very specific and controlled way.
In practical terms, a laser produces a highly controlled beam of light. Unlike normal light, which spreads in multiple directions and contains many wavelengths, laser light is:
This is what allows it to target structures within the skin with precision and selectivity.
What is a laser?
A laser produces a very narrow, focused beam of light that delivers energy into the skin in a very controlled way.
What makes it different from other light sources is how precise it is.
Each laser operates at a specific wavelength, and that wavelength determines what it targets in the skin, whether that’s pigment, blood vessels or water within the tissue.
This is why different lasers exist. They are not interchangeable. Each is designed to treat a particular set of indications.
A laser system is made up of three essential components:
Together, these components create the laser beam that is ultimately delivered to the skin during treatment.
How does laser light reach the tissue?
When a laser is activated, energy is generated and delivered into the skin as a focused beam of light.
Because that light is uniform and directional, it can penetrate the skin in a controlled way and interact with specific targets (usually something you want to remove, heal or rejuvenate).
The depth of penetration and the type of interaction depend on the wavelength being used, which is why wavelength selection is so important.
In practice, wavelength determines three things:
Different wavelengths are absorbed by different chromophores. Some are preferentially absorbed by melanin, others by haemoglobin or water. If the wavelength doesn’t match the target, the treatment simply won’t be effective.
The depth of action of a laser depends on its absorption by the target (water, haemoglobin, and/or melanin. The more a laser is absorbed by a target (or targets), the more superficial its action. The less it is absorbed, the deeper it penetrates in the skin. This is why certain lasers are used for surface pigmentation, while others are better suited to deeper vascular or structural concerns.
Wavelength also influences how much energy is absorbed by surrounding tissue. Poor wavelength selection increases the risk of unwanted heating, which can lead to complications such as burns or post-inflammatory hyperpigmentation.
This is where the concept of selective photothermolysis becomes important.
Rather than heating everything in the treatment area, the goal is to deliver energy that is selectively absorbed by the intended target (such as a tattoo), while minimising damage to surrounding tissue.
When wavelength, pulse duration and energy settings are aligned correctly, you achieve controlled thermal damage where it’s needed, and little to no damage where it isn’t. This promotes the body’s natural healing response, which is often what we’re after.
Wavelengths and laser therapy for the skin
Laser wavelengths fall within different regions of the electromagnetic spectrum, including visible and infrared light. Each wavelength behaves differently within the skin, which is why multiple types of therapy laser treatment exist.
Common laser wavelengths used in aesthetic and dermatological treatments include:
In practice, this means:
This is why wavelength selection directly affects both safety and results.
For example:
We’ll delve into more detail on this in a future Laser 101 blog.
What are chromophores?
When laser light enters the skin, it is absorbed by specific targets known as chromophores. These are molecules within the skin that absorb light energy, including:
Tattoo ink and pigments
Each chromophore absorbs light differently depending on the wavelength used. This ability to absorb energy is known as the absorption coefficient. The higher the absorption coefficient at a particular wavelength, the more effective that laser will be at targeting that structure.
For example, wavelengths in the 585–595 nm range, such as those used in pulsed dye lasers, are strongly absorbed by haemoglobin. This makes them particularly effective for treating vascular concerns. Other wavelengths are absorbed by melanin, allowing for the treatment of pigmentation or hair, while water-absorbing wavelengths are commonly used for skin resurfacing.
Pulse duration and timing
Lasers do not always deliver energy continuously. Many systems deliver energy in controlled pulses.
Pulse duration affects how energy is transferred into the skin and how heat builds within the target.
In practical terms, this allows you to:
More advanced systems, such as picosecond lasers, deliver energy extremely quickly, creating additional mechanical effects alongside heat.
This expands what can be treated, particularly in areas such as pigmentation and tattoo removal.
Making sense of laser therapy
Understanding these fundamentals makes navigating laser devices much, much easier.
If you’re looking to add a laser treatment to your aesthetic clinic, we highly recommend looking through our skin concerns page. Here you can learn a little more about how different lasers treat various skin concerns. This allows you to choose a device based on what you want to treat.
If you have questions about laser therapy, we’d be happy to help. Get in touch today if you require support with choosing the perfect laser device for your clinic.
