Measurement of Gaussian laser beam radius using the knife-edge technique: Improvement on data analysis

Departamento de Física, Universidade Federal da Paraíba, João Pessoa 58051-970, Paraíba, Brazil.
Applied Optics (Impact Factor: 1.78). 02/2009; 48(2):393-6. DOI: 10.1364/AO.48.000393
Source: PubMed


We revisited the well known Khosrofian and Garetz inversion algorithm [Appl. Opt.22, 3406-3410 (1983)] that was developed to analyze data obtained by the application of the traveling knife-edge technique. We have analyzed the approximated fitting function that was used for adjusting their experimental data and have found that it is not optimized to work with a full range of the experimentally-measured data. We have numerically calculated a new set of coefficients, which makes the approximated function suitable for a full experimental range, considerably improving the accuracy of the measurement of a radius of a focused Gaussian laser beam.

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Available from: Emerson de Lima, Apr 04, 2014
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    • "The detection laser spot is positioned at the tip of the cantilever during all experiments, resulting in the highest response for all the flexural modes of vibration. The Gaussian spot size on the cantilever, determined using the knife-edge method [23], was 12 µm for LD DE and 29 µm for LD EX . The deflection of the cantilever Δz is geometrically related to the displacement ΔD of the laser spot on the position sensitive detector (PSD) [24]. "
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