Abstract

Supercontinuum generation in air using tightly focused femtosecond laser pulses was investigated experimentally. Broadband white-light emission covering the whole visible spectral region was generated. Spectral broadening extended only to the blue side of the fundamental frequency due to the phase modulation induced by the strong ionization of air. Numerical simulation was also performed to confirm the spectral broadening mechanism. A constant UV cutoff wavelength close to $400\mathrm{nm}$ was observed in the supercontinuum spectrum. This phenomenon indicated that intensity clamping still plays a role in tight focusing geometry.

© 2011 Optical Society of America

Tightly focused femtosecond laser pulse in air: from filamentation to breakdown

Xiao-Long Liu, Xin Lu, Xun Liu, Ting-Ting Xi, Feng Liu, Jing-Long Ma, and Jie Zhang
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Arrest of self-focusing collapse in femtosecond air filaments: higher order Kerr or plasma defocusing?

Olga Kosareva, Jean-Francois Daigle, Nikolay Panov, Tiejun Wang, Sima Hosseini, Shuai Yuan, Gilles Roy, Vladimir Makarov, and See Leang Chin
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Oval-like hollow intensity distribution of tightly focused femtosecond laser pulses in air

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Third and fifth harmonic generation by tightly focused femtosecond pulses at 2.2 μm wavelength in air

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Effect of focusing element-induced aberrations on filamentation and supercontinuum emission in ambient air

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Opt. Express 29(10) 14668-14681 (2021)