We present the experimental realization of transverse mode conversion in an optical fiber via an optically induced long-period grating. The transient gratings are generated by femtosecond laser pulses, exploiting the Kerr effect to translate intensity patterns emerging from multimode interference into a spatial refractive index modulation. Since these modulations exist only while the pump beam is present, they can be used for optical switching of transverse modes. As only a localized part of the grating was written at a time and the probe beam was co-propagating with the pump beam the required pulse energies could be reduced to 120 nJ which is about a factor of 600 lower than in previous quasi-continuous-wave experiments. Accompanying numerical simulations allow a better understanding of the involved effects and show excellent agreement to the experimental results.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/OE.22.024951 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Half-Metallic Antiferromagnetic 2D Nonlayered CrSe Nanosheets.
ACS Nano
December 2024
SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Republic of Korea.
Half-metallic magnetism, characterized by metallic behavior in one spin direction and semiconducting or insulating behavior in the opposite spin direction, is an intriguing and highly useful physical property for advanced spintronics because it allows for the complete realization of 100% spin-polarized current. Particularly, half-metallic antiferromagnetism is recognized as an excellent candidate for the development of highly efficient spintronic devices due to its zero net magnetic moment combined with 100% spin polarization, which results in lower energy losses and eliminates stray magnetic fields compared to half-metallic ferromagnets. However, the synthesis and characterization of half-metallic antiferromagnets have not been reported until now as the theoretically proposed materials require a delicate and challenging approach to fabricate such complex compounds.
View Article and Find Full Text PDFHuman motion similarity evaluation based on deep metric learning.
Sci Rep
December 2024
College of Sports, Beihua University, Jilin, 132000, China.
In order to eliminate the impact of camera viewpoint factors and human skeleton differences on the action similarity evaluation and to address the issue of human action similarity evaluation under different viewpoints, a method based on deep metric learning is proposed in this article. The method trains an automatic encoder-decoder deep neural network model by means of a homemade synthetic dataset, which maps the 2D human skeletal key point sequence samples extracted from motion videos into three potential low-dimensional dense spaces. Action feature vectors independent of camera viewpoint and human skeleton structure are extracted in the low-dimensional dense spaces, and motion similarity metrics are performed based on these features, thereby effectively eliminating the effects of camera viewpoint and human skeleton size differences on motion similarity evaluation.
View Article and Find Full Text PDFMultifunctional SERS Chip for Biological Application Realized by Double Fano Resonance.
Nanomaterials (Basel)
December 2024
Guangdong Provincial Key Laboratory of Photonics Information Technology, Guangdong University of Technology, Guangzhou 510006, China.
The in situ and label-free detection of molecular information in biological cells has always been a challenging problem due to the weak Raman signal of biological molecules. The use of various resonance nanostructures has significantly advanced Surface-enhanced Raman spectroscopy (SERS) in signal enhancement in recent years. However, biological cells are often immersed in different formulations of culture medium with varying refractive indexes and are highly sensitive to the temperature of the microenvironment.
View Article and Find Full Text PDFInsights from a year of field deployments inform the conservation of an endangered estuarine fish.
Conserv Physiol
December 2024
U.S. Bureau of Reclamation Bay-Delta Office, 801 I St., Suite 140, Sacramento, CA 95814, USA.
Freshwater fishes are increasingly facing extinction. Some species will require conservation intervention such as habitat restoration and/or population supplementation through mass-release of hatchery fish. In California, USA, a number of conservation strategies are underway to increase abundance of the endangered Delta Smelt (); however, it is unclear how different estuarine conditions influence hatchery fish.
View Article and Find Full Text PDFPrecise Light-Driven Polarity of Stationary Phase for Regulating Gradient Separation of Liquid Chromatography.
Anal Chem
December 2024
Department of Chemistry, National Demonstration Centre for Experimental Chemistry Education, Yanbian University, Yanji City 133002, Jilin Province, China.
Generally, the traditional stationary phase for liquid chromatography is the key part, but with an in situ immutable property, leading to many separation limitations. Based on the former exploration of photosensitive gas chromatography, we successfully prepared a photosensitive monolithic capillary silica column with high light transmission, taking advantage of the reversible cis-trans isomerism of azobenzene. And the cis-trans isomerism has launched an effective, reversible, and precise control on the liquid chromatographic retention behavior just by photoinduction according to the theoretical basis of a good correlation between photoinduction time, -azobenzene ratio, and chromatographic retention factor () ( > 0.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!