Lasers emitting at wavelengths of >1.4 μm present a much reduced ocular hazard compared with shorter wavelength devices because absorption of radiation by the water of the eye prevents high intensities due to focusing at the retina. The holmium:YLF (YLiF4) laser generates a wavelength of 2.08 μm and thus falls in the class of eye-safe lasers. Corneal damage may still occur, but with a threshold of 3.5 J/cm2 for O-switched pulses, this is not a problem with the low-energy output pulses from our range finder.

© 1982 Optical Society of America

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