A framework is proposed for infrared (IR) absorption microscopy in the far-field with a spatial resolution below the diffraction limit. The sub-diffraction resolution is achieved by pumping a transient contrast in the population of a selected vibrational mode with IR pulses that exhibit alternating central minima and maxima, and by probing the corresponding absorbance at the same wavelength with adequately delayed Gaussian pulses. Simulations have been carried out on the basis of empirical parameters emulating patterned thin films of octadecyltrichlorosilane and a resolution of 250 nm was found when probing the CH₂ stretches at 3.5 μm with pump energies less than ten times the vibrational saturation threshold.
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http://dx.doi.org/10.1364/OE.20.029694 | DOI Listing |
Anal Chem
January 2025
Center for Advanced Materials Research & Faculty of Arts and Sciences, Beijing Normal University, Zhuhai 519087, P. R. China.
The development of long-wavelength near-infrared II (NIR-II, 900-1700 nm) dyes is highly desirable but challenging. To achieve both red-shifted absorption/emission and superior imaging capabilities, a donor-acceptor-donor (D-A-D) xanthene core was strategically modified by extending π-conjugated double bonds and enhancing electron-donating properties. Two dyes named and were synthesized and exhibited notably red-shifted absorption/emission peaks at 942/1250 and 1098/1450 nm, respectively.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, The Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, State Key Laboratory of Molecular Neuroscience, and Department of Chemical & Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China.
The two contradictory entities in nature often follow the principle of unity of opposites, leading to optimal overall performance. Particularly, aggregation-induced emission luminogens (AIEgens) with donor-acceptor (D-A) structures exhibit tunable optical properties and versatile functionalities, offering significant potential to revolutionize cancer treatment. However, trapped by low molar absorptivity (ε) owing to the distorted configurations, the ceilings of their photon-harvesting capability and the corresponding phototheranostic performance still fall short.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Department of Chemistry, New York University, New York, New York 10003, USA.
The water trimer, as the smallest water cluster in which the three-body interactions can manifest, is arguably the most important hydrogen-bonded trimer. Accurate, fully coupled quantum treatment of its excited intermolecular vibrations has long been an elusive goal. Here, we present the methodology that for the first time allows rigorous twelve-dimensional (12D) quantum calculation of the intermolecular vibration-tunneling eigenstates of the water trimer, with the monomers treated as rigid.
View Article and Find Full Text PDFSmall
January 2025
Biomaterials Research Center, School of Biomedical Engineering, Southern Medical University, Guangzhou, 510515, P. R. China.
Near-infrared (NIR)-triggered type-I photosensitizers are crucial to address the constraints of hypoxic tumor microenvironments in phototherapy; however, significant challenges remain. By selecting an electron-deficient unit, a matched energy gap in the upper-level state is instrumental in boosting the efficiency of intersystem crossing for the type-I electron transfer process. 2-Cyanothiazole, an electron acceptor, is covalently linked with N, N-diphenyl-4-(thiophen-2-yl)aniline to yield a multifunctional photosensitizer (TTNH) that exhibits intrinsic NIR absorbance and compatible T energy levels, facilitating both radiative and nonradiative transitions.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2025
Nanoscale Solid-Liquid Interfaces, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Schwarzschildstraße 8, 12489 Berlin, Germany.
MXenes are two-dimensional (2D) materials with versatile applications in optoelectronics, batteries, and catalysis. To unlock their full potential, it is crucial to characterize MXene interfaces and intercalated species in more detail than is currently possible with conventional optical spectroscopies. Here, we combine ultra-broadband ellipsometry and transmission spectroscopy from the mid-infrared (IR) to the deep-ultraviolet (UV) to probe quantitatively the composition, structure, transport, and optical properties of spray-coated TiCT MXene thin films with varying material properties.
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