TY - JOUR

T1 - Propagation of axisymmetric beams by means of gauss-fourier expansion

AU - Ruschin, S.

N1 - Publisher Copyright:
© 1993 SPIE. All rights reserved.

PY - 1993/4/22

Y1 - 1993/4/22

N2 - A method is presented for describing the propagation of axisymmetric beams by expansion into Gaussian beams which are displaced axially relative to the entrance plane. If the position of the Gaussian beams waists and their widths are properly chosen, the coefficients of the expansion can be found by means of Fast Fourier Transform (FFT) procedures. One disadvantage of propagation algorithms based on FFT's is that their range is limited by aliasing effects. The propagation length is then enhanced usually by enlarging the entrance plane and padding with zeros the transverse field range thus enlarging the size of vectors without increasing field details. An alternative approach is that of subdividing the propagation length into smaller steps and eliminating the leaking aliased field by introducing absorbing layers close to the boundaries of the transverse range. The method described here has significantly reduced aliasing effects due to the bound character of the Gaussian functions, thus enlarging the range of propagation of a single step. Another advantage of the method is that the sampling points are evenly distributed in the r2 co-ordinate, following linearly the power distribution across the radius of axisymmetric beams.

AB - A method is presented for describing the propagation of axisymmetric beams by expansion into Gaussian beams which are displaced axially relative to the entrance plane. If the position of the Gaussian beams waists and their widths are properly chosen, the coefficients of the expansion can be found by means of Fast Fourier Transform (FFT) procedures. One disadvantage of propagation algorithms based on FFT's is that their range is limited by aliasing effects. The propagation length is then enhanced usually by enlarging the entrance plane and padding with zeros the transverse field range thus enlarging the size of vectors without increasing field details. An alternative approach is that of subdividing the propagation length into smaller steps and eliminating the leaking aliased field by introducing absorbing layers close to the boundaries of the transverse range. The method described here has significantly reduced aliasing effects due to the bound character of the Gaussian functions, thus enlarging the range of propagation of a single step. Another advantage of the method is that the sampling points are evenly distributed in the r2 co-ordinate, following linearly the power distribution across the radius of axisymmetric beams.

UR - http://www.scopus.com/inward/record.url?scp=85075775623&partnerID=8YFLogxK

U2 - 10.1117/12.143851

DO - 10.1117/12.143851

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AN - SCOPUS:85075775623

SN - 0277-786X

VL - 1834

SP - 18

EP - 23

JO - Proceedings of SPIE - The International Society for Optical Engineering

JF - Proceedings of SPIE - The International Society for Optical Engineering

T2 - Laser Energy Distribution Profiles: Measurement and Applications 1992

Y2 - 16 November 1992

ER -