We report on observations of conical third harmonic emission that emerges during supercontinuum generation produced by self-focusing and filamentation of high (20-200 kHz) repetition rate 180 fs, 1035 nm pulses from an amplified Yb:KGW laser in various nonlinear crystals and glasses: YAG, sapphire, YLF, LiF, CaF, MgF, LiSAF, fused silica and BK-7 glass. We show that conical third harmonic generation is a phase-matched four-wave mixing process, where noncollinear phase matching is achieved by means of reciprocal lattice vector, inversely proportional to the period of nanograting, which is inscribed by femtosecond filament in the volume of nonlinear material. The existence of a particular period required to phase match conical third harmonic generation was indirectly verified by investigations of periodicity features of high and low spatial frequency laser-induced periodic surface structures, in which matter is reorganized in a similar fashion.
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http://dx.doi.org/10.1364/OE.444901 | DOI Listing |
Am J Sports Med
January 2025
Department of Sports Medicine, Peking University Third Hospital, Institute of Sports Medicine of Peking University, Beijing, China.
Black corals are key species of marine ecosystems. They can be found in dense aggregations worldwide, but some parts of the world remain totally unexplored. This is the case of the Mesophotic Coral Ecosystem of Mo'orea where the Under the Pole scientific expedition explored mesophotic ecosystems between 60 and 120 m depth and focused on whip black corals.
View Article and Find Full Text PDFJ Clin Microbiol
December 2024
School of Public Health and Tropical Medicine, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia.
J Chem Theory Comput
November 2024
Department of Chemistry, Kyungpook National University, Daegu 41566, South Korea.
Ophthalmic Physiol Opt
January 2025
Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
Aim: To develop an accommodating, wide-angle, schematic eye for emmetropia and myopia in which spectacle refraction and accommodation level are input parameters.
Method: The schematic eye is based on an earlier unaccommodated refraction-dependent eye for myopia developed by Atchison in 2006. This has a parabolic gradient index lens and parameters derived from biometric and optical measurements on young adults.
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