Laser & The Skin
When the laser light strikes the stratum corneum _______ percent is reflected due to the sudden change between the lasing medium and the surface of the skin.
5%
What does L.A.S.E.R stand for?
Light Amplification by Stimulated Emission of Radiation
What is ground state energy level?
The state of an atom before energy is applied to it
Properties of Laser light:
- Monochromatic
- Coherent
- Polarized
- Specific target chromophore
The wavelength of a laser depends on the state of the electrons energy when it drops to a lower _________.
Orbit
List the 4 ways laser light interacts with the skin
1. Reflection
2. Penetration/Transmission
3. Scattering/Diffusion
4. Absorption
Thermal Diffusion Time
The amount of time it takes for the laser to diffuse from the hair follicle to the stem cells
What is a photon?
A particle of light
Why is a set of mirrors important in a laser?
Photons reflect off the mirrors when traveling back and forth in the lasing medium. The mirrors cause photons to travel in a coherent manner.
Wavelength of a Diode laser
800-810 nm
Why is it important to cool the skin before, during, and after laser treatment?
1. To prevent hyper/hypopigmentation
2. Prevent burning and blistering of the skin
3. For client comfort
Selective Photothermolysis
Destruction of a target chromophore without thermal injury to the surrounding tissue
What can cause electrons in the ground state to become excited?
Heat, light, electricity
Properties of IPL
- Polychromatic
- Non coherent
- Depolarized
- No specific chromophore targeting
Nd YAG Q Switched laser has a wavelength of __________ and is used to remove __________ and __________ tattoos.
1064nm
Dark blue
Black
4 ways you can reduce the amount of laser light reflection on the skin
1. Remove makeup
2. Remove dirt
3. Remove oil
4. Remove deodorant
5. Remove oil
6. Remove sunscreen
7. Remove water
8. Remove jewelry
Population Inversion
The number of atoms in the ground state versus the number in the excited state
ONE way photons are created in a laser
Spontaneous emission;
Lasing medium is pumped, the electrons take on more energy and become excited to a higher energy. They then relax to ground state. When electrons release energy it is emitted as a photon.
What is different about the mirrors in the laser, why are they this way?
One is half silvered, which allows some of the photons to escape, creating laser light.
Wavelength of the Ruby laser
694nm
As the wavelength of the laser increases ⤴️ the absorption level of melanin _____________.
Decreases ⬇️
Fluence
The amount of energy delivered into the tissue and chromophores, measured in joules/cm2
List the 5 parts of the atom
1. Proton
2. Neutron
3. Nucleus
4. Electron
5. Orbit/Valence
What is frequency measured in?
Hertz
Specific wavelengths, will target specific ____________.
Chromophores