Lasers

Question 1

What does the accronym LASER stand for?

Answer 1

Light Amplification by Stimulated Emission of Radiation

Question 2

What do Nd:YAG and holmium:YAG stand for

Answer 2

Nd:YAG = Neodymium-doped Yytrium Aluminium Garnet

Ho:Yag = Holmium Yytrium Aluminium Garnet

Question 3

What are the wavelengths of diode, Nd:Yag, Ho:Yag & CO2 lasers

Answer 3

Diode 980nm

Nd:Yag 1064nm

Ho:Yag 2100nm

CO2 10,600nm

Question 4

List the 4 possible fates of laser energy/tissue interactions.

When laser energy is absorbed, what are the possible laser tissue interactions? & at roughly what temperatures do these occur?

Answer 4

1. ABSORTION - required for surgical effects of the laser
   a) Photo-ablation/vapourisation - complete tissue ablation >100’C
   b) Photo-coagulation - irreversible thermal necrosis but without immediate tissue destruction
   c) Carbonisation - char formation >100’C++
2. Reflection - reflected away from target area causing undesired damage at another site
3. Transmission - target tissue completely penetrated, can rx in damage to undesirable tissue
4. Scatter - away from target site