论文信息 - Near-field modification of femtosecond laser beam to enhance single-shot pulse filamentation in glass medium

Near-field modification of femtosecond laser beam to enhance single-shot pulse filamentation in glass medium

In this paper, a study of the effect of a transparent dielectric medium (soda-lime glass placed after an objective lens) on femtosecond pulse filamentation in Corning Eagle2000 glass is presented. The dielectric medium placed after the objective lens increases the effective numerical aperture of the focusing lens and tightly focuses the beam to elevate the power density in a tiny focal volume. A single-shot narrow filamentary void of diameter 3.8 μm is observed to propagate as long as 700 μm in Corning Eagle2000 glass. Elevated optical intensity confined in the small focal volume and low ionization losses per unit length in the narrow plasma column collectively enhance the filamentary propagation of the ultra-short pulse in bulk glass. The applied technique also offers an approach to control the length and width of a filamentary void structure in a transparent dielectric medium.

[1] Arnaud Couairon,et al. Filamentation length of powerful laser pulses , 2003 .

[2] G. Mourou,et al. Self-channeling of high-peak-power femtosecond laser pulses in air. , 1995, Optics letters.

[3] F. Théberge,et al. Filamentation nonlinear optics , 2007 .

[4] Qihuang Gong,et al. Filamentation and temporal reshaping of a femtosecond pulse in fused silica , 2003 .

[5] Olga G. Kosareva,et al. The propagation of powerful femtosecond laser pulses in optical media : physics, applications, and new challenges , 2005 .

[6] S. Juodkazis,et al. Effect of refractive index-mismatch on laser microfabrication in silica glass , 2003 .

[7] A. Couairon,et al. Self-guided propagation of ultrashort IR laser pulses in fused silica. , 2001 .

[8] J. Marburger,et al. Self-focusing: theory , 1975, International Quantum Electronics Conference, 2005..

[9] Gilbert D. Feke,et al. Realization of numerical aperture 2.0 using a gallium phosphide solid immersion lens , 1999 .

[10] Qihuang Gong,et al. Multiple foci and a long filament observed with focused femtosecond pulse propagation in fused silica. , 2002, Optics letters.