Working with Lasers
description
Transcript of Working with Lasers
![Page 1: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/1.jpg)
Working with Lasers
Deakin University
![Page 2: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/2.jpg)
Working with Lasers
Part 1: Background informationPart 2: Laser hazards to considerPart 3: Laser classificationPart 4: Laser safetyPart 5: Lasers at Deakin
![Page 3: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/3.jpg)
Part 1: Background Information• How lasers work• Why they are hazardous
![Page 4: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/4.jpg)
How Lasers work
• Laser Material (gas, liquid, solid, semiconductor)• Pump/Excitation Mechanism (discharge, flashlamp, laser)• Feedback Mechanism (mirror)• Output coupler (semi-transparent mirror)
![Page 5: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/5.jpg)
Why Lasers Are HazardousLaser light differs from light from other sources in
several ways:– Monochromatic (single wavelength)– Directional (Low Divergence)– Coherent
Laser light can pose an extreme hazard because a lot of energy is concentrated in a small area
![Page 6: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/6.jpg)
Why Lasers Are Hazardous
2 Main Factors
1. Collimation Effects : Collimated light means the photons emitted from the laser are in parallel not scattered like conventional light sources. Therefore more light can be introduced into the eyes compared to other light sources.
![Page 7: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/7.jpg)
Why Lasers Are Hazardous
2 Main Factors
2. Spot Size Effects : Radiation in the 400 – 1400nm region is brought to a sharp focus on the retina. This can increase the radiant exposure (irradiance) by approx 100,000 times.
![Page 8: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/8.jpg)
Part 2: Laser Hazards to Consider
1.Beam Hazards• Damage to the eye• Damage to the skin
2. Non-Beam Hazards
• Electrical safety• Chemical safety• Airborne
contaminants• Noise safety
![Page 9: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/9.jpg)
Beam hazards- Effects on Eyes and Skin by
wavelength
![Page 10: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/10.jpg)
Non-beam Hazards: Chemical
Laser dyes – most dyes are carcinogenic
Insulation Materials – Dusts, Fibres (Wear Masks)
Optical Fibers – Eye hazards
Solvents – flammability
![Page 11: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/11.jpg)
Non-beam Hazards: Electrical
• High voltages – Always ensure covers are in place.
• 240 v – No uninsulated connections permitted.
• Don’t leave live circuits unattended.
![Page 12: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/12.jpg)
Non-beam hazards:Gases
Compressed gases – toxicity, flammability and asphyxiation hazards.
Vacuum system – implosion issues with glass vessels. Safety glasses must be worn.
![Page 13: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/13.jpg)
Non-beam hazards: Cryogenics
Liquid nitrogen – cold burns and asphyxiation hazard.
Liquid N2 can condense O2 from the atmosphere and may cause an explosion.
Ensure you have been trained in the correct way to handle liquid N2.
Do not accompany full Liquid N2 Dewars in Lifts.
![Page 14: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/14.jpg)
Non-beam hazards: Laser Generated Air
Contaminants• Laser cutters can generate
hazardous dust particles
• Familiarise yourself with any potential by-products
• Consult MSDS, reference books and supervisors
• Use adequate extraction
![Page 15: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/15.jpg)
Lab Hazards Combinations
High Voltage40 kV
Water Cooling
Insulation Materials
Oil Cooling(Hot Oil)
Laser Beam200W
Vacuum System
High Temp 800C
Ionising Radiation
Toxic Gases
UV from Discharge
![Page 16: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/16.jpg)
Part 3: Laser Classification
![Page 17: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/17.jpg)
Factors affecting Laser classification level
6 main factors to consider:
- Wavelength
- Continuous Wave or Pulsed Operation
- Power or Pulse Energy
- Repetition Rate (PRF)
- Beam Diameter & Profile
- Beam Divergence
![Page 18: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/18.jpg)
Approx. Power Limits for CWVisible Wavelengths Only
Class 4 Unsafe for eyesUnsafe for skin
0.5W Class 3B Unsafe for eyesGenerally safe for skin
5mW Class 3R Safe with (0.25 s.) aversion response no viewing aids
0.5W Class 2MVisible wavelengths only
Safe with no viewing aids
1mW Class 2Visible wavelengths only
Safe with (0.25 s.) aversion response including viewing aids
0.5W Class 1M Safe with no viewing aids
220μW to 0.4μW
Class 1 No precautions required
Laser Classification System
![Page 19: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/19.jpg)
Old Laser Classification System
Approx. Power Limits for CWVisible Wavelengths Only
Class 4 Unsafe for eyesUnsafe for skin
0.5 W Class 3B Unsafe for eyesGenerally safe for skin
5 mW Class 3A Safe with (0.25 s.) aversion response no viewing aids
1 mW Class 2Visible wavelengths only Safe with (0.25 s.) aversion
response including viewing aids
220μW to 0.4μW
Class 1 No precautions required
![Page 20: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/20.jpg)
Laser Safety Precautionsby classification
Class 1 Lasers : - Safe
Class 1M Lasers: - No viewing aids
Class 2 Lasers : - Safe with aversion response
(No staring)
Class 2M Lasers: - Safe with aversion response
(No staring); No viewing aids
Class 3R Lasers : - No Staring, No viewing aids,
(also old Class 3A lasers) Unsafe outside visible range
![Page 21: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/21.jpg)
Laser Safety Precautionsby classification, cont.
Class 3B Lasers : - Unsafe for eyes, generally
safe for skin
Class 4 Lasers : - Unsafe for eyes, unsafe for
skin
![Page 22: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/22.jpg)
Part 4: Laser safety
![Page 23: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/23.jpg)
General Laser Lab Safety
Never directly view a laser beam.
Never point a laser pointer at a person.
Never over-ride interlocks
Never remove covers from equipment without approval from supervisors – laser, high voltages and other hazards are present.
![Page 24: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/24.jpg)
General Laser Lab Safety, cont. Clothing: Long sleeve clothing should be worn to
protect skin. Wear enclosed footwear in labs.
Jewelry: watches & rings which could reflect beams should not be worn.
Viewing Aids: Never use microscopes, telescopes, magnifying glasses etc to view laser beams
![Page 25: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/25.jpg)
Special Considerations forClass 3B & 4 Lasers• Avoid Exposure of eyes & skin
• Work in Controlled Areas
• Diffuse Reflections are Hazardous
• Use Beam Stops
• Use Eye Protection
• Post Warning signs
• Interlocks Required
![Page 26: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/26.jpg)
Laser Lab design A labyrinth style entryway into labs, giving a safe
area to put on safety equipment (PPE).
A storage rack for laser safety eyewear (labelled with wavelengths etc).
Laser operators should not be seated at beam height to avoid possible exposure
![Page 27: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/27.jpg)
Laser hazard controlsHierarchy of controls Elimination Substitution Isolation Engineering Administration PPE
![Page 28: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/28.jpg)
Laser ControlsEngineering• Protective Housings• Remote Interlocks• Access Panels• Master Switches• Enclosed beam baths
![Page 29: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/29.jpg)
Laser ControlsAdministrative• Laser Safety Officer• Safe Working Procedures (SWPs)• User registration• Record keeping• Correct Labelling of device and
area• Medical surveillance (Eye tests)
Laser Warning signs
![Page 30: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/30.jpg)
Medical Surveillance>Eye testing before and after the use of
Class 3B & Class 4 lasers is recommended
Visual acuity Ishihara test Amsler Grid
![Page 31: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/31.jpg)
Laser ControlsPPE
The main form of protective equipment is protective eyewear, but when using Class 4 lasers protective clothing and footwear must also be worn
![Page 32: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/32.jpg)
Eye protection
>Ensure the correct wavelengths are covered (not all safety eyewear materials are the same) otherwise the safety goggles may be offering no protection for the laser you are working with
![Page 33: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/33.jpg)
A note about Eye safe lasers
Lasers with emission wavelengths longer than 1400nm are often labelled as ‘eye-safe’ because wavelengths greater than 1400nm are strongly absorbed in the cornea & lens of the eye rather than the relatively more sensitive retina.
High powered or pulsed lasers at these wavelengths will still burn the cornea and cause severe eye damage. Corneal injuries are very painful.
A laser labelled eye-safe should be treated the same as any other laser – with extreme caution. NEVER stare at a laser beam.
![Page 34: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/34.jpg)
Part 5: Lasers at Deakin
Majority of lasers are Low Power, Class 1 & 2 Laser Pointers
Laser, Chemical and Electrical safety procedures must be followed
No Laser use after hours or by untrained personnel
![Page 35: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/35.jpg)
Deakin laser procedures
All work should be covered by a Project Safety Plan which has been signed off by a lab manager and the University Radiation Safety Officer
A Laser Hazard Identification checklist must be completed for Laser classes 3 and above
Class 3B and Class 4 lasers should have a written Safe Working Procedure on hand – guidelines available
![Page 36: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/36.jpg)
Laser pointersLaser pointers are effective tools when used properly. The following considerations should be observed when using them:
• Use only laser pointers with AS/NZS 2211 classification Class 1 or Class 2.
• Do not use or purchase a laser pointer that has a stated emission level of greater than 1mW
• Ensure Class 2 lasers are labelled correctly "Caution: Laser Radiation. Do not stare into the beam. Class 2 Laser Product."
• Never look directly into the laser beam.• Never point a laser beam at a person.• Do not aim the laser at reflective surfaces.• Do not allow children to use laser pointers.
![Page 37: Working with Lasers](https://reader035.fdocuments.us/reader035/viewer/2022070408/568143a9550346895db03219/html5/thumbnails/37.jpg)
Conclusion
Consider all the implications of your laser use, including those around you.
Never stare at a laser beam
Always wear correct Laser Safety Glasses
Report any lab problems or concerns to your supervisor and/or the University radiation safety officer