arXiv subjects

Jefferson E. Tsuchida

Publications and source records attributed to Jefferson E. Tsuchida.

4 recordsLinked to original sources

arXiv2026

Rotation angle sensing via polarization-dependent mode superposition in a hollow-core fiber with two-fold symmetry

Hollow-core photonic crystal fibers (HCPCF) have experienced tremendous advancements recently, leading to remarkable demonstrations of transmission loss reduction and deeper understanding of their guidance fundamentals. Indeed, this progress has entailed investigations into various HCPCF designs, allowing for attaining diverse properties of interest such as ultralow loss, polarization filtering, and specific modal operation. Among HCPCFs with tailored modal characteristics are fibers displaying microstructures with modified symmetry, which allow for changing the loss hierarchy between the guided modes, hence favoring the propagation of higher-order modes. In this context, we here demonstrate the realization of an angle sensor utilizing a tubular HCPCF with a two-fold symmetric cladding. This specific fiber design enables the generation of an output intensity profile resulting from the superposition of LP01 and LP11-like modes, whose excitation and resulting output intensity spatial distribution are dependent on the polarization angle of the incident light. Thus, by rotating the input beam's polarization and analyzing the evolution of the resulting output profile, we characterized a rotation angle sensor exhibiting a sensitivity of 25 counts/degree and an estimated resolution of 0.3°. We understand that this work broadens the framework of HCPCF applications, demonstrating that symmetry-modified hollow-core fibers can act as a promising platform for advanced sensing scenarios and polarimetric characterizations.

physics.optics↗

arXiv2025

In-series Multimode Interference Sensors and Fabry-Perot Interferometers for Enhanced Wavelength Shift Resolving Capabilities

We report on the development of a refractive index sensor obtained by using a singlemode-multimode-singlemode (SMS) structure and a Fabry-Perot interferometer (FPI) set into an in-series configuration. Due to the self-imaging phenomenon, the SMS structure - formed by splicing a no-core fiber between two singlemode fibers -, provides a broad spectral peak whose central wavelength position is sensitive to variations in the refractive index of the medium surrounding the fiber. In turn, thanks to the in-series SMS-FPI configuration, the sensor's reflection spectrum exhibits the SMS spectral signature modulated by FPI fringes. This readily allows for reducing the width of the spectral features monitored during the sensing measurements, thus enhancing the capabilities of adequately resolving the corresponding spectral shifts. The FPIs reported in this investigation have been fabricated by using two different methods, namely by forming an air-gap FPI between the cleaved ends of two singlemode optical fibers, and by casting a polymeric film onto a connectorized fiber end tip. In the first configuration, the distance between the two cleaved fiber ends could be varied to tune the FPI's free spectral range, hence allowing for tailoring the widths of the spectral oscillations to be monitored during the sensing measurements. Alternatively, the second configuration, while avoiding the use of motorized translation stages, provides a more versatile option for applications. Thus, we understand that our work expands the application of multimode interference and FPIs in sensing scenarios, providing new opportunities for probing physical and chemical parameters by exploring their combined response.

physics.optics↗

arXiv2025

Refractometry with filled antiresonant capillary fibers

We demonstrate the realization of refractometric measurements relying on the study of the transmission spectrum of filled capillary fibers. In this method, the fiber is filled with a material with a lower refractive index than that of the capillary and, due to antiresonant guidance mechanism, a characteristic transmission spectrum alternating high and low attenuation regions is obtained. The refractive index data is hence extracted by analyzing the spectral positions of the fiber transmission bands. While this method holds broad applicability for diverse materials, we specifically applied this technique to characterize agarose gels, due to their interest as a promising optical material. By analyzing the transmission spectra across the 600-900 nm wavelength range, we determined the dispersion trend for agar gels prepared with varying water and glycerol concentrations and estimated their first-order Sellmeier coefficients. The reported refractometric method provides a simple and promising means for characterizing the dispersion properties of a wide range of materials, including gels, solids, and liquids, also opening new possibilities for the development of new refractive index sensing platforms.

physics.optics↗

arXiv2024

Analytical assessment of the total loss in tubular hollow-core fibers during their fabrication process

Hollow-core photonic crystal fibers (HCPCFs) have become a key enabling technology for addressing a broad spectrum of fundamental and applied needs. Indeed, recent advancements achieved by the HCPCF research community have led to significant progress, establishing these fibers as the lowest-loss optical fibers currently available for use in the visible and ultraviolet ranges. However, the fabrication process of HCPCFs demands costly infrastructure, and achieving ultralow-loss fibers remains a complex technical challenge as numerous fabrication attempts are typically required to optimize their performances. Therefore, predicting these fibers' performances before experimental fabrication is highly desirable. In this work, we tackle this task by analytically assessing the total loss in tubular-lattice HCPCFs during their fabrication process. By considering the variation in the microstructure's geometrical parameters during fabrication and the different sources of loss, we estimate expected loss levels and identify the conditions for loss minimization. We understand that our research provides valuable insights into the fabrication process of hollow-core fibers, offering a predictive approach to evaluate the fibers' performance before their experimental realization. By determining optimal conditions considering geometry, fabrication constraints, and loss figures, we believe that our work contributes to the ongoing efforts to further reduce the loss levels in HCPCFs.

physics.optics↗