Transcript Laser Safety

Laser Safety
Andras Kis
Zettl group safety talk
11/16/2006
Laser Components
• Light Amplification by Stimulated Emission of Radiation
OPTICAL RESONATOR
LASER
beam
Active medium
high reflectance
mirror
output coupler
mirror
excitation
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
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
Retinal damage
<400, >1400 nm
Burns, cataracts
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 mW
Visible 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 123
CF 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 II
Class IIIa with expanded beam
Class IIIa with small beam
Class IIIb
Class 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