1. Laser Safety Laser Beam Containment Effects from beam exposure
Learning Experience
Laser Beam Containment
Students working on a laser in a shared laser lab risked causing eye injury to others due to stray laser beams.
One student was aligning a laser and did not contain all the stray beams. One of the beams projected from the laser table at eye-level to other students work in the lab.
The stray laser beam hit the back of a monitor and was discovered by other students working in the lab. These students should have been warned to stay away from laser table until the adjustments to the beam were complete. The beams also should have been better contained.
Lasers can produce intense, directed radiation that does not decrease with distance.
Lasers are classified by intensity and wavelength.
Picture of a stray laser beam: a near-miss reported in one of our laboratories
Laser Classifications
Effects from beam exposure
Class IIIa – laser pointers
Visible light with intensity < 5 mW
Burn to retina can occur from prolonged eye exposure.
Class IIIb – lasers used for dynamic light scattering
Visible light with intensity between 5 and 500 mW
Near-IR light < 500 mW – cannot see it to look away
Immediate eye injury can result from brief exposure.
Class IV – usually pump lasers for other lasers
Any laser > 500 mW
Even exposure to scattered light causes eye damage. Wear protective laser goggles at all times.
Ultraviolet – burns on cornea and lens
Visible to near-IR – burns on retina, possible blindness due to bleeding in eye