Photonics Lab Safety
Photonics Lab Hazards
- Laser Safety
- Lasers are grouped into classes. Each class describes what safety precautions are associated with each type of laser
- Safety Definitions:
- Specular Reflections- Reflections from flat or curved mirror-like surfaces. May increase the area of exposure by widening the beam
- Diffuse Reflections- Reflections from a surface that cause the beam to reflect in many directions. Particular directions may be difficult to predict and therefore dangerous.
- Class I
- Label as class I.
- Usually applies to lasers that are shielded to prevent any kind of exposure, even if laser inside is classified higher. For example, the laser within a CD player or laser printer.
- Cannot, under normal operating conditions, produce a hazard.
- Class II
- Yellow caution label.
- Usually low power (1 mW), visible light. Applies to some visible HeNe lasers. Class IIa applies to some bar code readers and other equipment not intended for viewing.
- No known skin or fire hazard. Produces normal reflex (closing eye or turning head) when bright light is exposed to eye. Not really considered dangerous because the natural reflex prevents any long exposure. But, any prolonged exposure may cause damage. It's like looking at the sun for extended periods of time. Your mother told you not to.
- Class IIIa
- Danger label and output aperture label attached to equipment. Should have laser emission indicator so you know the laser is in use.
- Power output between 1mW - 5mW. Example: some visible continuous wave HeNe lasers.
- No known skin or fire hazard. Can produce spot blindness if un-protected eye is exposed through collective optical devices (ie. fibers, lenses, etc).
- Class IIIb
- Red Danger label and aperture label must be attached. Must have a key to prevent unauthorized use, a emission indicator and a 3-5 second time delay.
- Power output between 5mW = 500mW.
- Skin may be burned at higher power levels and some materials may catch fire. Will definitely cause eye damage.
- Class IV
- Red Danger labels and aperture labels must be attached. Must have key lockout switch and use interlocks to prevent system being used without protective covers. Emission indicators must show when laser is in use. Mechanical shutter must be used to block beam
- Power output >500mW
- Skin may be burned, materials may catch fire. Reflected beam is just as dangerous as primary beam to the eye.
- General Guidelines:
- Be aware of the laser hazards present.
- Know the appropriate laser Class and take the necessary precautions.
- Follow operation instructions carefully.
- Never point a laser beam at a person.
- Never look directly into the laser beam.
- Never look directly into specular, mirror-like reflections of the laser beam.
- Do not wear any objects on your hands and wrists that may cause specular reflection, such as watches or jewelry.
- Do not let the laser beam or any of its reflections leave the experiment table unless the experiment requires it.
- Keep all the beams in a plane parallel to the experiment table.
- Do not bring your eye level down to the plane of the laser beam, keep the beam axis below typical standing and sitting positions.
- Close your eyes if you bend down to pick something up off the floor.
- Use beam stops and carefully plan the placement and movement of optical elements.
- Laser light scattered by rough surfaces, such as paper is harmless to the eye at low power levels. However, it is still a good idea not to stare at bright diffuse spots for a long time.
- Leave the room lights ON when possible. The eye’s pupils open wide in a dark room and present a larger target for dangerous laser light.
- Use common sense and be alert at all times
- Wear your goggles! and make sure they are matched to the appropriate wavelength.
- Chemical Safety
- We have a few chemicals that we use regularly in the Optics lab. See Fiber Etch SOP. The MSDS are also available outside the IML lab.
- DeContam - cleaning agent
- Isopropyl Alcohol:
- Used to clean off connections
- Used to strip plastic jacket from Optical fibers
- Use purple nitrile gloves.
- Keep in small container. We do not use much at any one time.
- Do not leave cap off for very long. It is a solvent and will evaporate.
- HF (hydroflouric acid) & BOE (buffered oxide etch):
- Used to etch glass
- Very Dangerous. Use all PPE!
- Put on nitrile gloves................. Put on acid apron.................... Put on splash goggles.
- Put on face mask...................... Put on HF gloves..................... Finished!
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- Electrical Safety
- We do have high-voltage sources in the optics lab. Be careful and use common sense.
- General Awareness:
- Laser disconnects are located on the west wall, beside the white board.
- Only experienced personnel are to open the laser disconnects.
- Moving laser power supplies often results in excessive water to spill on the floor. Wipe up immediately.
- Do not open encased equipment while it is still plugged in.
- Avoid contact with energized electrical circuits.
- Disconnect the power source before servicing or repairing electrical equipment.
- When it is necessary to handle equipment that is plugged in, be sure hands are dry and, when possible, wear nonconductive gloves and shoes with insulated soles.
- If it is safe to do so, work with only one hand, keeping the other hand at your side or in your pocket, away from all conductive material. This precaution reduces the likelihood of accidents that result in current passing through the chest cavity.
- Minimize the use of electrical equipment in cold rooms or other areas where condensation is likely. If equipment must be used in such areas, mount the equipment on a wall or vertical panel.
- If water or a chemical is spilled onto equipment, shut off power at the main switch or circuit breaker and unplug the equipment.
- If an individual comes in contact with a live electrical conductor, do not touch the equipment, cord or person. Disconnect the power source from the circuit breaker or pull out the plug using a leather belt.
- Cleanroom Safety
- See IML Safety page
- Miscellaneous Safety tips
- Glass fibers are very small and can break through the skin.
- To prevent this please clean up any stray fibers you may see.
- Wear shoes in the lab since small pieces of glass may have fallen on the ground.
- Wear purple nitrile gloves when cleaving fibers to prevent small bits from getting in fingertips.
Other Research Assistants
- Don't mess with someone's experiment or demonstration setup or any fibers on the tables.
- Optical fibers are very fragile and have been known to break spontaneously.
- Please be aware and avoid excessive use of tape.
- Only allow experienced lab assistants to use and distribute the scotch tape.
Laser safety sources: Princeton's
Laser Safety page , University of
Tennessee's Laser Safety page , Sam's Laser