We characterize the spectral response of a distributed-feedback resonator when subject to a thermal chirp. An AlO rib waveguide with a corrugated surface Bragg grating inscribed into its SiO top cladding is experimentally investigated. We induce a near-to-linear temperature gradient along the resonator, leading to a similar variation of the grating period, and characterize its spectral response in terms of wavelength and linewidth of the resonance peak. Simulations are carried out, showing good agreement with the experimental results and indicating that the wavelength of the resonance peak is a result only of the total accumulated phase shift. For any chirp profile we are able to calculate the reflectivities at the resonance wavelength, and this information largely explains how the linewidth of the resonance changes. This result shows that the increase in linewidth is governed by the increase of the resonator outcoupling losses.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/OE.26.004892 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Physiological Root Resorption of Deciduous Teeth: An ATR-FTIR Approach.
J Clin Med
December 2024
Department of Medical, Oral and Biotechnological Sciences, University "G. D'Annunzio" of Chieti-Pescara, Via dei Vestini 31, 66100 Chieti, Italy.
: The study exploited, for the first time, Attenuated Total Reflectance-Fourier Transform-InfraRed (ATR-FTIR) spectroscopy on human dental pulps at different timings of root resorption (RR) to deepen the biological mechanisms occurring in deciduous teeth (De) during their replacement with permanent ones. : N:36 dental pulps from sound De were divided into the following: G0 (no RR); G1 (RR less than 1/3 of root length); G2 (RR not exceeding 2/3 of root length); and G3 (RR more than 2/3 of root length). Samples were analyzed by ATR-FTIR, and the spectral data were submitted to univariate (One-way ANOVA and Tukey's multiple comparison tests; statistical significance set at < 0.
View Article and Find Full Text PDFEfficacy of Segmentation for Hyperspectral Target Detection.
Sensors (Basel)
January 2025
Department of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Beer Sheva blvd 1, Beer-Sheva 84105, Israel.
Algorithms for detecting point targets in hyperspectral imaging commonly employ the spectral inverse covariance matrix to whiten inherent image noise. Since data cubes often lack stationarity, segmentation appears to be an attractive preprocessing operation. Surprisingly, the literature reports both successful and unsuccessful segmentation cases, with no clear explanations for these divergent outcomes.
View Article and Find Full Text PDFEnhanced Vernier Effect in Cascaded Fiber Loop Interferometers for Improving Temperature Sensitivity.
Sensors (Basel)
December 2024
Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communication, Institute of Photonics Technology, Jinan University, Guangzhou 510632, China.
This work presents a high-sensitivity temperature sensing system utilizing an enhanced Vernier effect implemented in cascaded fiber loop interferometers. High-sensitivity temperature sensors based on the Vernier effect have broad application prospects, but the sensitivity of traditional measurement schemes is difficult to improve further due to the limited variation in the difference between two free spectrum ranges (FSRs). Our sensing system incorporates two fiber loop interferometers and a single-mode fiber to form a Vernier spectral response, characterized by two complementary optical filter responses.
View Article and Find Full Text PDFCorrection: Tian et al. Genome-Wide Identification of the DnaJ Gene Family in Citrus and Functional Characterization of in Response to Citrus Huanglongbing. 2024, , 11967.
Int J Mol Sci
January 2025
MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, Guangdong Provincial Key Laboratory of Laser Life Science, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510631, China.
In the original publication [...
View Article and Find Full Text PDFOptimizing Photobiomodulation Radiometric and Spectral Parameters In Vitro to Enhance Angiogenesis and Mitochondrial Function.
Int J Mol Sci
December 2024
Laboratory for Functional and Metabolic Imaging (LIFMET), Institute of Physics, Swiss Federal Institute of Technology (EPFL), Station 3, 1015 Lausanne, Switzerland.
Photobiomodulation (PBM) therapy, a therapeutic approach utilizing low-level light, has garnered significant attention for its potential to modulate various biological processes. This study aimed at optimizing and investigating the effects of PBM on angiogenesis and mitochondrial metabolic activity. In vitro experiments using human umbilical vein endothelial cells (HUVECs) and vascular smooth muscle cells (VSMCs) were performed to assess PBM's impacts on cell migration, proliferation, endogenous protoporphyrin IX production, mitochondrial membrane potential, Rhodamine 123 fluorescence lifetime, mitochondrial morphology, and oxygen consumption.
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!