First working laser device from whom and when?
Theodore Maiman
1960
What is the LASER acronym?
Light Amplification Stimulated Emission of Radiation
Ordinary light characteristics?
multiple wavelengths (colors)
non-collimated
incoherent
Laser irradiation characteristics?
monochrome
coherent (in phase; same wavelength)
collimated (parallel)
Unit of wavelength
micron 10^-6
nanometer 10^-9
unit of pulse duration
PICO, Nano
Unit of pulse repetition
Hz
Unit of energy
J or mJ
Unit of power average and peak
W
Unit of energy density/fluence
J/cm^2
Unit of power density
W/cm^2
What is population inversion?
- more atoms in excited state, more opportunities for stimulated emission to occur
- situation that allows avalanche principle to occur
ionizing radiation?
charged portion (electron) given enough energy to break away from atom
non-ionizing radiation?
laser light
enough energy for excitation to a higher state ONLY
What laser in visible range?
Argon
I.e. Diagnodent
What lasers in near-IR for SOFT tissue?
Nd:YAG
Diodes
What lasers in mid-IR for HARD tissue?
Er:YAG
Er:Cr:YSGG
What laser in far-IR for SOFT tissue?
CO2
Modes of Operation with mechanically gated-foot panel or electronically gated
continuous wave
