The influence of a focused polarized Gaussian beam on image formation was studied. We show that the position of the tip with reference to the center of the beam involves asymmetry in the intensity map. A comparison between s and p polarization can be made, owing to the definition of both a three-dimensional polarized Gaussian beam and a three-dimensional object. This result implies that the best way to scan a sample consists in moving it and not the tip; moreover, focusing the incident light to get a higher signal-to-noise ratio must be done carefully with respect to the sample period.
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http://dx.doi.org/10.1364/ol.24.001587 | DOI Listing |
In this paper, the focusing and tight-focusing properties of radially polarized (RP) Bessel-Gaussian (BG) rotationally-symmetric power-exponent-phase vortex beam (RPVBs) were investigated theoretically and experimentally. Based on the theory of vector beam, the propagation and tight-focusing models were derived to reveal the focusing and tight-focusing properties of the RP-BG-RPVBs by numerical simulation. Then, the experimental setup was established to validate that the RP-BG-RPVBs presented the fan-shaped and polycyclic intensity distribution, which possessed the features of RP beams, BG beams, and RPVBs, similarly.
View Article and Find Full Text PDFThis study investigates the intricate properties of linearly polarized circular Airyprime-Gaussian vortex beams (CApGVBs) in tightly focused optical systems. We explore the relationship between self-focusing and tight focusing of CApGVBs by adjusting the main ring radius. By refining vortex pair parameters, we show that the intensity distribution depends significantly on whether the arrangement is axial or off-axis.
View Article and Find Full Text PDFA transversely isotropic diode-pumped solid-state laser is used to obtain an orthogonally dual-polarization nonplanar circular mode (NCM) under off-axis pumping in the strictly degenerate cavity. Each polarized component of the NCM outside the cavity is revealed to be individually localized on the ray orbits forming a nonplanar surface, in which the transverse patterns display multiple spots well positioned on a circular structure. An analytical representation is established to explore polarization-resolved components of the NCM by utilizing the Gaussian wave packet to directly correlate with geometrical rays.
View Article and Find Full Text PDFPhotochem Photobiol Sci
January 2025
CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535, Coimbra, Portugal.
Solvatochromism exhibited by azobenzene-4-sulfonyl chloride (here abbreviated as Azo-SCl) has been investigated in a series of non-polar, polar-aprotic and polar-protic solvents. The UV-vis spectra of Azo-SCl exhibit two long-wavelength bands, observed at 321-330 nm (band-I) and 435-461 nm (band-II), which are ascribed to the π*-π (S ← S) and π*-n (S ← S) transitions, respectively. The shorter wavelength band indicates a reversal in solvatochromism, from negative to positive solvatochromism, for a solvent with a dielectric constant of 32.
View Article and Find Full Text PDFChemSusChem
January 2025
Fuzhou University, College of Chemistry, Xueyuan Road 2, 350108, Fuzhou, CHINA.
Elevating the long-wavelength activation of photocatalysts represents a formidable approach to optimizing sunlight utilization. Polythiophene (PTh), although renowned for its robust light absorption and excellent conductivity, is largely overlooked for its potential as a photocatalyst due to the swift recombination of photogenerated charge carriers. Herein, we unveil that the strategic introduction of an aromatic ring containing varying nitrogen content into PTh instigates polarized charge distribution and facilitates the narrowing of the band gap, thereby achieving efficient photocatalytic activities for both hydrogen and hydrogen peroxide generation.
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