5 Lasers Introduction to Lasers Laser Acupuncture Laser

5. Lasers

Introduction to Lasers

Laser Acupuncture, Laser Scalpel and Laser W/R Head

Laser Virtual Mouse/Keyboard

Laser Scanner

Lasing Conditions

Theory of Laser

General Optical Resonator and Laser Transverse Mode

Gaussian Beam

Gaussian Beam (Cont’)

Laser Longitudinal Mode Optical resonance: where λ: wavelength of the resonating frequency, L: length of the cavity, m : an integral Eg. laser diode : cavity length = 300 m; Al. Ga. As : gap wavelength 800 nm How many wavelength will fit into the cavity ?

Multi-(Longitudinal) Mode Laser v: velocity of the wave in cavity c : speed of light n : refractive index of cavity material Cavity resonance frequency Spacing between the adjacent frequency ( frequency spacing ) Wavelength spacing 0 : free space value of the wavelength

Characteristics of Laser Diode

Modulation of Laser Diode

Numerical Analysis for Modulation of Laser Diode

Radiation of Laser Diode Radiation pattern Output spectrum

Typical Characteristics of Diode Light Sources

Laser Safety Rules 1) Wear special goggles 2) Never looking the primary laser beam or into the specular reflection of a beam 3) Higher power beams should be terminated 4) Skin protection should be worn at higher power levels ( e. q. heavy white cloth ) 5) Special precaution for invisible laser beam