Z-scan technique for elliptic Gaussian beams

• Published in: Applied physics. B, Lasers and optics Vol. 77; no. 1; pp. 71 - 75
• Main Authors: TSIGARIDAS, G, FAKIS, M, POLYZOS, I, PERSEPHONIS, P, GIANNETAS, V
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.08.2003
• Subjects: Beam trapping, self-focusing and defocusing; self-phase modulation; Beam trapping, self-focusing, and thermal blooming; Beams (radiation); CCD cameras; Energy use; Exact sciences and technology; Far fields; Fluctuation; Fundamental areas of phenomenology (including applications); Gaussian beams (optics); Lasers; Nonlinear optics; Optical susceptibility, hyperpolarizability; Optics; Physics; Transmittance; Gaussian beam; CCD camera; Ultrashort pulse; Non linear material; Elliptic shape; Carbon sulfides; Theoretical study; Optical materials; Experimental study; Pulsed lasers; Nonlinear optics; Z scan
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-003-1225-4

A novel z-scan technique suitable for elliptic Gaussian beams is proposed. It is based on the direct measurement of the beam's semiaxes in the far field instead of the irradiance transmitted through an aperture, as in the case of circular beams. This technique overcomes, for the first time, the insurmountable obstacles encountered when a z-scan technique based on transmittance measurements is used in the case of elliptic beams. The experimental procedure of this technique is realized using a CCD camera connected to a laser beam profiler, and has the advantage of being insensitive to beam pointing instability and energy fluctuations. It also reveals the different influence of the optical non-linearities on the two principal semiaxes of the elliptic beam.