1. We don’t want this! lesions Optic nerve Fluorescein angiograph of retina after laser irradiation

2. We don’t want this! When the beam struck my eye I heard a distinct popping sound, caused by a laser-induced explosion at the back of my eyeball. My vision was obscured almost immediately by streams of blood floationg in the vitreous humor, and by what appeared to be particulate matter suspended in the vitreous humor. It was like viewing the world through a round fishbowl full of glycerol into which a quart of blood and a handful of black pepper have been partially mixed. There was local pain within a few minutes of the accident, but it did not become excruciating

3. Instruction is mandatory! Training is essential for your safety!

5. Light Amplification by the Stimulated Emission of Radiation Monochromatic Monochromatisch (smal spectrum) Coherent in de tijd (fase blijft behouden) Coherent in de ruimte (interferentie, spikkel patroon) Kleine divergentie (goed focuseerbaar)

6. Directional

7. Coherent

8. Laser components: Lasing medium: Optical cavity

9. Spanningsbron gelijkstroom + Plasma buis 100% reflector Uitgang- spiegel De drie belangrijkste onderdelen van een laser: pomp om medium te exciteren medium met optische versterking optische trilholte De onderdelen van een laser

10. Gas He - Ne632.8 nm Ar514.5 nm + …. Kr647 nm + …. CO 2 10.6 mm Vaste stof Robijn (Cr 3+ )694 nm Nd: YAG1064 nm Halfgeleider AlGaAs780 - 870 nm InGaAsP1300-1600 nm Vloeistof Rhodamine 6G580 - 630 nm Het medium bepaalt de golflengte van het licht Het laserende medium

11. Focuseerbaarheid f Ideale bundel: Fictief beeld punt laser Focus laser bundel d SS’ h0h0 h1h1 

14. PULSED LASERS

15. Pupil Aperture of the eye. Normal range of 2 - 7 mm. Range decreases with age. 7 mm is used for hazard calculations. Cornea: Living, protective tissue Transparent, ~ 0.5 mm thick Mean index of refraction = 1.376 (  70% of the refractive power) High metabolic rate (rejuvenating itself in 24 to 48 hours)

17. The retina is an extension of the brain and consists of several complex layers of nerve cells. Made up of rods and cones - rods for night and peripheral vision, cones for color and resolution.

18. 315 - 400 nm

19. Near Ultraviolet Wavelengths (UVA) 315 - 400 nm  Most of the radiation is absorbed in the lens of the eye.  The effects are delayed and do not occur for many years (e.g.; cataracts). Far Ultraviolet (UVB) 280 - 315 nm and (UVC) 100 - 280 nm  Most of the radiation is absorbed in the cornea.  Snow blindness/welder's flash) will result with high doses. Visible (400 -760 nm) and Near Infrared (760 - 1400 nm)  Most of the radiation is transmitted to the retina *.  Overexposure may cause flash blindness or retinal burns and lesions. Far Infrared (1400 nm - 1 mm)  Most of the radiation is transmitted to the cornea.  verexposure to these wavelengths will cause corneal burns.

21. 250 Watt Laser Moving at 1 Inch per Second 250 Watt Laser in Single Pulses hotdog Chicken wing

22. Electrical Hazard Uncovered electrical terminals. Improperly insulated electrical terminals. Hidden "power up" warning lights. Lack of training. "Buddy system" not being practiced Non-earth-grounded or improperly grounded laser equipment. Non-adherence to the OSHA lock-out standard (29CFR1910.147). Excessive wires and cables on floor that create fall or slip hazards

24. Laser Dyes and Solvents Dyes are used in some lasers as a lasing medium. These dyes are complex organic compounds that are mixed in solution with certain solvents. Some dyes are highly toxic or carcinogenic, and great care must be taken when handling them, preparing solutions, and operating lasers that contain these dyes. A Material Safety Data Sheet must be made available to anyone working with these dyes.

25. From ANSI Z136.1 (2000): causes for accidents: Unanticipated eye exposure during alignment Misaligned optics and upwardly directed beams Available eye protection not used Equipment malfunction Improper methods for handling high voltage Intentional exposure of unprotected personnel Operators unfamiliar with laser equipment Lack of protection for ancillary hazards Improper restoration of equipment following service Eyewear worn not appropriate for laser in use Unanticipated eye/skin exposure during laser usage Inhalation of laser-generated air contaminants Ignition of fires of both a facility or personal nature Eye or skin injury of photochemical nature Failure to follow standard operating procedures (SOPs)

26. Engineering controls have eye protection for personnel protective housing with interlocks on removable parts a key-controlled master switch shall be provided the entire beam should be enclosed as much as possible warning light and sings should exist at the entrance be supervised by an individual with knowledge of laser safety have limited access to spectators have beam stops to terminate dangerous laser beams be designed to reduce diffuse and specular reflections not have a laser beam at eye level with people restrictions on windows and doorways to reduce exposure require disabling of the laser when it is not being used