We report the first realization of quasi-phase-matched (QPM) third harmonic generation in isotropic polymer films. Spin-coated thin films of ethyl-violet molecules dispersed in a polymer host (EV) were used as cubic nonlinear optical media because of their transparency at both the fundamental (1230 nm) and the third harmonic (410 nm) wavelengths. A passive layer of a UV-curable material was formed to compensate the phase shift between the two light waves after propagating through each EV layer. We fabricated a series of samples with 1~4 EV layers (0~3 alternatingly coated passive layers). The third harmonic output power showed a quadratic increase with the number of layers, providing a strong evidence for successful quasi-phase-matching. A conversion efficiency of 0.15% was observed with a 190 fs pulse input.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6219598 | PMC |
http://dx.doi.org/10.1038/s41598-018-34788-8 | DOI Listing |
Sci Rep
January 2025
Institute of Sustainable Energy, Universiti Tenaga Nasional, Jalan IKRAM-UNITEN, Kajang, 43000, Selangor, Malaysia.
The microgrid (MG) faces significant security issues due to the two-way power and information flow. Integrating an Energy Management System (EMS) to balance energy supply and demand in Malaysian microgrids, this study designs a Fuzzy Logic Controller (FLC) that considers intermittent renewable sources and fluctuating demand patterns. FLC offers a flexible solution to energy scheduling effectively assessed by MATLAB/Simulink simulations.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Laser Thermal Laboratory, Department of Mechanical Engineering, University of California, Berkeley, California 94720, United States.
Spectrochim Acta A Mol Biomol Spectrosc
December 2024
Department of Chemistry, KTH Royal Institute of Technology, Teknikringen 29, SE-100 44 Stockholm, Sweden. Electronic address:
Nano-FTIR spectroscopy is a technique where atomic force microscopy (AFM) and infrared (IR) spectroscopy are combined to obtain chemical information with a lateral resolution of some tens of nm. It has been used to study numerous solid surfaces and recently also liquids including water have been examined by separating the liquid from the AFM tip by a thin lid. However, although the water stretching vibrations are significantly more intense than the bending vibration in conventional IR spectroscopy, only the bending vibration has been observed in nano-FTIR spectroscopy so far.
View Article and Find Full Text PDFSci Rep
December 2024
Department of physics, Faculty of Science, Malayer University, Malayer, Iran.
This study investigates the optical properties of carbon nanotubes (CNTs) and silicene nanotubes (SiNTs) under the influence of external magnetic fields, focusing on their linear and nonlinear optical responses. A tight-binding model is employed to analyze the effects of magnetic fields on the electronic band structure, dipole matrix elements, and various optical susceptibilities of zigzag CNTs and SiNTs. The results reveal significant magnetic field-induced modifications in both linear and nonlinear optical spectra.
View Article and Find Full Text PDFJ Am Acad Orthop Surg
December 2024
From the Department of Orthopaedic Surgery, University of Utah, Salt Lake City, UT (Graesser), the Washington University School of Medicine in St. Louis, Mallinckrodt Institute of Radiology, St. Louis, MO (Parsons), and the Department of Orthopaedic Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO (Olafsen, Dy, and Brogan).
Traumatic peripheral nerve injuries represent a spectrum of conditions and remain challenging to diagnose and prognosticate. High-resolution ultrasonography and magnetic resonance neurography have emerged as useful diagnostic modalities in the evaluation of traumatic peripheral nerve and brachial plexus injuries. Ultrasonography is noninvasive, is able to rapidly interrogate large areas and multiple nerves, allows for a dynamic assessment of nerves and their surrounding anatomy, and is cost-effective.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!