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English - Walter Schottky Institut
Laser safety Prof. Dr. Martin S. Brandt Walter Schottky Institut Technische Universität München Impact of light on the eye Ultraviolett light: corneal and lens clouding (snow blindness) Hazard above 1 W Visible and infrared light: Destruction of the retina Hazard above 1 mW Walter Schottky Institut Technische Universität München Impact of light on the skin Sunburn Skin cancer (malignant melanoma) visible: Hazard above 10 mW/cm2 UV: Hazard above 1 W/cm2 Walter Schottky Institut Technische Universität München Impact of light on equipment 1 mW Hazard depends on material: Paper above 1 mW Metal above 0.5 W Walter Schottky Institut Technische Universität München Accidents Smoke 2% Rauch 2% Feuer 4% Fire 4% Verbrennung Burns der Haut 12% (skin) 12% Eyes Verletzung der Augen (protection failed) 3% 3% (Schutz versagt) Verletzung der Augen Eyes (bad protection) (schlechter Schutz)21% 21% Walter Schottky Institut Verletzung der Eyes Augen (no protection) 21% (kein Schutz) 46% All accidents alle involving eyes Verletzungen 70% der Augen 70% Technische Universität München Lasers involved in accidents verdoppelt doubled 2% 2% Nd:YAG Nd:YAG 26% 26% Ti:Sapphire Ti:Saphir 2% Rubin 5% Diodes Dioden6% 6% HeNe HeNe 6% 6% Farbstoff 8% Dye 8% Argon17% 17% Argon CO22 12% 12% Walter Schottky Institut Technische Universität München Power (W) Laser classification Wavelength (nm) Class 1: Class 1M: Class 2: Class 2M: Class 3R: Class 3B: Class 4: Old classification not dangerous (e.g. fully shielded) <25µW usually safe, unsafe when optical instruments are used <25µW/1mW power so low, that lid closes quickly enough (visible light <1mW) unsafe when optical instruments are used <1mW 5-fold power of class 1M und 2M lasers 1…5mW always dangerous 5…500mW even dangerous when scattered diffusely (e.g. at a wall) >500mW Class 1 Class 3A&B Class 2 visible 3A&B Class 3B Class 4 The classification of pulsed layers follows analogous concepts. Walter Schottky Institut Technische Universität München Labelling Argon SICHTBARE UND UNSICHTBARE LASERSTRAHLUNG BESTRAHLUNG VON AUGE ODER HAUT DURCH DIREKTE ODER STREUSTRAHLUNG VERMEIDEN Diodes LASERSTRAHLUNG NICHT DEM STRAHL AUSSETZEN LASER KLASSE 3B NACH EN 60825-1:1994 LASER KLASSE 4 NACH EN 60825-1:1994 P0=10 W =333-514 nm Walter Schottky Institut Nd:YAG SICHTBARE UND UNSICHTBARE LASERSTRAHLUNG BESTRAHLUNG VON AUGE ODER HAUT DURCH DIREKTE ODER STREUSTRAHLUNG VERMEIDEN LASER KLASSE 4 NACH EN 60825-1:1994 P0=5 mW =780-1310 nm P0=300 W PP=100 MW t=10 ns F=Einzelpuls bis 300 Hz =266, 355, 532, 1024 nm Technische Universität München Labelling Power (W) + Wavelength (nm) Walter Schottky Institut Technische Universität München Use of laser goggles is mandatory! Walter Schottky Institut Technische Universität München Use of warning signs and warning lights is mandatory! Two different types of warning signs ! WSI Walter Schottky Institut ZNN Technische Universität München Summary Avoid unintentional exposure to light: Technical and organisatorial provisions against reflected or scattered irradiation When adjusting: Attentuate beam until safe Always use eye protection: Correct goggles Skin protection (visible above 10 mW/cm2, UV earlier!): Gloves, long sleeves Fire protection (officially above 0.5 W): Due not use inflammable materials near beam (paper, plastics, styropor) Designate rooms where laser of classes 3B and 4 are used Use red warning lamp when class-4 lasers are switched on Enter labs only after ok from colleagues inside Noncomplinace can be prosecuted by WSI and government institutions Walter Schottky Institut Technische Universität München
