laser safety andras kis zettl group safety talk 11/16/2006
TRANSCRIPT
Laser Safety
Andras KisZettl group safety talk
11/16/2006
Laser Components
• Light Amplification by Stimulated Emission of Radiation
Associated hazards:
1. Laser Beam: eye injury, burns, skin cancer (UV), fire hazard
2. Active medium: toxic chemicals or gases (organic dyes, BeO in Ar lasers, HF, HeCd, HeHg, HeSe)
3. Excitation source: high voltage, water cooling
OPTICAL RESONATOR
excitation
Active medium
LASERbeam
high reflectancemirror
output couplermirror
Human Eye- laser beam can be focused by cornea and the lens to a very tight spot on the retina
400-1400 nm<400, >1400 nm
<400, >1400 nm
Burns, cataracts
Retinal damage
Eye Injury
Eye Injury From A Pulsed Laser
Skin Burns
• CO2 laser reflected from a metal surface
Types of laser eye exposure
Laser hazard classes
• Classification by wavelength and output power, according to their ability to produce damage
Class Power Remarks Typical examples
I Very low or beam completely enclosed
•Inherently safe,•No possibility of exposure
CD, DVD drives, laser printers…
II 1 mWVisible only
•Staring into the beam is hazardous•Eye protected by aversion response
Supermarket laser scanners, some pointers
IIIa 1-5 mW •Aversion may not be adequate Laser pointers
IIIb 5-500 mW •Direct exposure is a hazard Ar laser in Birge 123CF microscope in B219
IV >500 mW •Exposure to direct beam and scattered light is eye and skin hazard•Fire hazard
Laser ablation setup in Birge 266
Labels on setups
Class IIClass IIIa with expanded beam
Class IIIa with small beamClass IIIbClass IV
Safety measures
• Be informed
• Eyewear for classes IIIb, IV for everybody in the room
• Beam paths above >200 mW should be guided through tubes
• Highest risk during alignment, optical setup modification
IIIb and IV requirements
• EHS 280 Laser Safety Training
• EHS 281 Laser Safety Retraining (every 3 years)
• On the Job Training – provided by PI/supervisor & documented in the Activity Hazard Document
• Laser eye exams
Links:
UCB laser safety
LBL laser safety