1. Introduction to Aesthetic Laser Concepts
Brief Overview
Gregory T. Absten
The Laser Training Institute™
Professional Medical Education Association, Inc.

2. Professional Medical Education Assn.
What is a Laser?
A Laser is an Electro-Optical device that converts electricity or ordinary light energy into intense beams of pure colors of light.
It stands for: Light Amplification by the Stimulated Emission of Radiation.
Professional Medical Education Assn.

3. What is the Electro-Magnetic Spectrum?
This is comprised of all the various wavelengths of electromagnetic energy (Radiation) that constitute light, electricity & radio waves. It ranges from the very small wavelengths of cosmic rays and x-rays, to the long wavelengths of Radio transmissions. Visible light is one part of this range, and each color is a different wavelength.
Professional Medical Education Assn.

4. What is the Electro-Magnetic Spectrum?
Different types of Lasers produce unique wavelengths of electro-magnetic energy, that range from the short wavelength ultraviolet lasers, through visible light, to long infrared wavelengths. Each type of Laser is different.
Professional Medical Education Assn.

5. What is the Laser Active Medium?
This is the material that actually produces the energy within the laser. Ignoring commercial marketing names for a moment, the Laser is usually named after this active medium.
The Carbon Dioxide Laser for instance uses that gas as the active medium, which emits an infrared wavelength of 10,600nm.
Professional Medical Education Assn.

6. Some Common Aesthetic Lasers & Wavelengths
Name Wavelength Example Use
Alexandrite nm infrared Hair Removal
Diode Variable 810nm-1400nm Hair Removal Veins
CuBr nm yellow Vascular
511nm green Pigmented lesions
Pulsed Dye nm yellow Vascular
Nd:Yag nm infrared Hair Removal Veins
CO ,600nm infrared Skin Resurfacing
Professional Medical Education Assn.

7. Energy Concepts
WATTS – (Power) Rate of Energy Delivery, but doesn’t say how much energy (Dose).
JOULES – (Dose) Amount of Energy Delivered, but doesn’t say how fast (Rate)
Joules = Watts x Time, i.e.;
1 Joule = 1000 watts x .001 seconds
Professional Medical Education Assn.

8. Energy Concepts
POWER DENSITY – Spot Size & Power Watts per Square Centimeter (W/cm2)
Concentration of the Power within the spot size. Analogous to a magnifying glass and the sun. Small spots burn (or ablate) because they are more intense. Large spots don’t burn as quickly because they are less intense. Spot size will change the power density faster than a change in power.
Professional Medical Education Assn.

9. Energy Concepts
ENERGY DENSITY – Spot Size & Dose Joules per Square Centimeter (J/cm2)
Concentration of the total “Dose” of light within the spot size. This considers both the Power Density and length of time. It is usually the treatment parameter for Aesthetic Laser use – i.e. 25J/cm2
Professional Medical Education Assn.

10. Professional Medical Education Assn.
Tissue Effects
Most Aesthetic Laser Tissue effects come from heating of specific target tissues when the light from the laser is selectively absorbed into that target.
Dark materials absorb more light and therefore generate more heat that light materials. Heat causes tissue death (hair removal), or inflammation (skin rejuvenation) at lower levels.
Professional Medical Education Assn.

11. Professional Medical Education Assn.
Tissue Effects
Adverse Tissue Effects can occur when the heat is not confined to the target tissue, but is either absorbed by or conducts into other skin components.
I.E.; Burns & blistering created in Laser Hair Removal when the melanin in darker skin absorbs the laser light as much or more as the hair follicle.
Professional Medical Education Assn.

12. Professional Medical Education Assn.
Eye Safety
Lasers can cause eye injury from direct or scattered light from the beam.
Retinal Injuries may be caused by those wavelengths that can pass through fluid into the eye’s interior.
These include the Diode, Pulsed Dye, Nd:Yag and CuBr lasers, among others.
Professional Medical Education Assn.

13. Professional Medical Education Assn.
Eye Safety
Lasers can cause eye injury from direct or scattered light from the beam.
Corneal (Surface) Injuries may be caused by those wavelengths that do not pass through fluid and are instead absorbed at the surface of the eye.
These include the CO2 and Er:Yag lasers, but the Power Density must be sufficient to cause a burn.
Professional Medical Education Assn.

14. Professional Medical Education Assn.
Eye Safety
Laser Safety Glasses MUST be worn by patients and personnel when they are within a hazardous distance around the laser output.
Laser Glasses are labeled with both the wavelength for specific lasers (i.e. 755nm for Alexandrite) and the Optical Density (O.D.) which indicates their level of protection. (Typically an O.D. of 4-7 for most medical procedures)
Professional Medical Education Assn.

15. Professional Medical Education Assn.
Eye Safety
The Glasses provide sufficient protection to allow you to safely treat patients by filtering out the light REFLECTED back from the patient’s skin.
Laser Glasses are NOT guaranteed to provide protection against DIRECT impacts into the eyes. Never point the Laser Output into anyone’s eyes.
Professional Medical Education Assn.

16. Professional Medical Education Assn.
More Information
Laser Training – Professional Medical Education Assn.
Laser Certification – National Council on Laser Excellence
Professional Society – American Society for Laser Medicine & Surgery
Professional Medical Education Assn.