Lasers safety precautions

Safety Precautions. When using the argon-ion laser, several precautions should be followed. 

This requires a laser pointer and a CD. Observe safety precautions do not aim the laser beam at anyone s eyes. Aim it, at approximately normal incidence, at the side of the CD that appears silvered. When the beam hits the tracks near the centre of the disc, a diffraction pattern is created (Fig. 1.10). This pattern is a two-dimensional analogue of X-ray diffraction from a three-dimensional crystal. 

Ethanol injection,bipolar electrocoagulation therapy, and argon coagulation are all methods used to restore patency of the esophageal lumen by producing tumor necrosis without the need for expensive laser equipment and the stringent safety precautions required for laser therapy. 

Lasers are classified into five classes (1, 2, 3a, 3b and 4) in ascending size of power output. Classes 1 and 2 are relatively low hazard and only emit light In the visible band. Classes 3a, 3b and 4 are more hazardous and the appointment of a laser safety officer Is recommended. All lasers should carry information stating their class and any precautions required during use. 

Powerful concentrated laser beams are useful for cutting and drilling and have to be guarded to prevent anyone getting into the beam path. Less powerful lasers, used for surveying for example, are not usually hazardous except perhaps to the eyes so precautions are advisable to prevent eye exposure to the beam. Lasers products are classified into four classes according to the risk of injury that they pose, and consequently the precautions that must be taken to protect people from their harmful effects detailed information on the classes and the safety precautions is published in BS EN 60825-1 1994, lEC 60825-1 1993 Safety of laser products. Equipment classification, requirements and user s guide. The classes are ... 

The majority of lasers used in semiconductor processing equipment are low powered (Class 2 or 3A) helium-neon (He-Ne) lasers used for alignment purposes. T q)ical fab equipment using these lasers includes some photolithographic steppers, wafer surface scanners, chemical vapor deposition (CVD) equipment, and some aligners. Safety precautions needed with these lasers are minimal assuming collecting optics are not used in the system. 

The major controls applicable to lasers used in semiconductor manufacturing are listed in Table 5. A detailed explanation of these precautions and others are contained in reference, American National Standards Institute (ANSI), Z136.1-1993, American National Standard for the Safe Use of Lasers.pl] Most laser safety programs within the U.S. semiconductor industry are based on this standard. 

The use of lasers is rapidly increasing in biomedical research. Typical uses for this instrument include photodensitometers, cell sorters, scanners, and similar optical devices. Workers who use laser sources must take precautions to prevent personal injury. The safety guidelines suggested here should be incorporated into a safety program for laboratories using lasers (438). 

Laser radiation, visible or invisible, can cause severe damage to the eyes and skin. Take proper precautions to prevent exposure to direct and reflected beams. Always follow manufacturers safety guidelines and consult the local safety office. For more detailed information, see caution below. 

---