Experimental determination of the maximum permissible exposure to picosecond laser pulses of 1.06 μ wavelength

Abstract

The uncertainties involved in the calculation of bottom quark (b-quark) crosssections in deep-inelastic scattering at HERA are studied in different phase space regions. Besides the inclusive b-quark cross-section, definitions closer to the detector acceptance requiring at least one high energetic muon from the semi-leptonic b-quark decay or a jet with high transverse energy are investigated. For each case the uncertainties due to the choice of the renormalisation and factorisation scales as well as the b-quark mass are estimated in the perturbative NLO QCD calculation and furthermore uncertainties in the fragmenation of the b-quark to a B-meson and in its semi-leptonic decay are discussed.

Comparison of macular versus paramacular retinal sensitivity to femtosecond laser pulses

“…This represents the lowest threshold reported for all near-IR studies. [4][5][6][7][8][9][10][11][12][13][14] The value was slightly less than the 0.43 J recorded 3 for the visible wavelength of 580 nm at 90 fs and one-third the value of 1.0 J measured at 1060 nm. 10 However, this 0.35 J was double the 0.17 J measured at 530 nm for 100 fs.…”

“…Figure 2 summarizes all MVL threshold data for single pulse exposures shorter than 10 ns. [3][4][5][6][7][8][9][10][11][12][13][14] Thresholds for the paramacular area were 1.6 times larger than the macular thresholds and this ratio held for both the 1 and 24 h data. Also, it is worth noting that the ED 50 thresh- old decreased by as much as 15% between the 1 and 24 h readings.…”

“…2 In this study we compare our results with those for both near-IR and visible wavelengths previously reported. [3][4][5][6][7][8][9][10][11][12][13][14] Laser-ocular tissue interaction studies for pulse widths below 1 ns are critical to the development of safety standards and in identifying hazards to the human eye from those systems presently operating in the near-IR regime. An understanding of laser-tissue interactions is basic to identifying the potential for injury and to applying therapeutic medical treatments to laser injury and disease.…”