Sugar Detection in Aqueous Solution Using an SMS Fiber Device.

We report on the fabrication and testing of a fiber optics sensor based on multimodal interference effects, which aims at the detection of different types of sweeteners dissolved in water. The device, which has a simple structure, commonly known as the SMS configuration, is built by splicing a segment of commercial-grade, coreless multimode fiber (NC-MMF) between two standard single-mode fibers (SMFs). In this configuration, the evanescent field traveling outside the core of the NC-MMF allows the sensing of the refractive index of the surrounding media, making it possible to detect different levels of sugar concentration.

Understanding and acceptance of the theory of evolution in high school students in Mexico.

The Theory of Evolution (TE) is the backbone of biology and is the best way to explain the diversity of species that exist on the planet. However, despite all the supporting evidence, TE remains poorly understood and accepted. In this study, the levels of acceptance and understanding of TE were measured, respectively, using the Inventory of Student Evolution Acceptance (I-SEA) and Knowledge of Evolution Exam (KEE) questionnaires, in high school students in Monterrey, Mexico (N = 370).

Phase memory of optical vortex beams.

Optical vortex beams are under considerable scrutiny due to their demonstrated potential for applications ranging from quantum optics to optical communications and from material processing to particle trapping. However, upon interaction with inhomogeneous material systems, their deterministic properties are altered. The way these structured beams are affected by different levels of disturbances is critical for their uses.

Refractometric Detection of Adulterated Milk Based on Multimode Interference Effects.

This paper reports on the refractometric detection of water-adulterated milk using an optical fiber sensor whose principle of operation is based on multimode interference (MMI). The device is manufactured in a simple way by splicing a segment of coreless multimode fiber (NC-MMF) between two single-mode fibers (SMFs); neither functionalization nor deposition of a sensing material is required. MMI takes place in the NC-MMF and, when fed with a broadband spectrum, a transmission peak appears at the output of the MMI device due to its inherent filter-like response, whose position depends on the effective refractive index (RI) of the medium surrounding the NC-MMF.

Passive high-frequency microrheology of blood.

Indicative of various pathologies, blood properties are under intense scrutiny. The hemorheological characteristics are traditionally gauged by bulk, low-frequency indicators that average out critical information about the complex, multi-scale, and multi-component structure. In particular, one cannot discriminate between the erythrocytes contribution to global rheology and the impact of plasma.

Multipoint fiber optics refractive index sensor based on multimode interference effects.

We demonstrate a fiber optics sensing structure for the measurement of the refractive index of liquid samples at multiple spatial locations simultaneously. The sensing architecture is all-fiber and consists of standard single-mode-multimode-single-mode multimodal interference (MMI) devices working in parallel. The spectral response of each MMI device is carefully engineered to have nonoverlapping responses, such that the entire system can be interrogated with a single broadband light source and single optical spectrum analyzer.

Tubulin Polarizability in Aqueous Suspensions.

We report accurate optical measurements of tubulin polarizability in aqueous suspensions. We determined the dependence of polarizability on tubulin concentration and on the suspension's pH, providing benchmark numbers for quantifying the optical response of this protein in various artificial and cellular environments. We compare our measurement data with a few estimates found in the previous literature and also with our simplified model estimations.

A highly sensitive fiber optic sensor based on two-core fiber for refractive index measurement.

A simple and compact fiber optic sensor based on a two-core fiber is demonstrated for high-performance measurements of refractive indices (RI) of liquids. In order to demonstrate the suitability of the proposed sensor to perform high-sensitivity sensing in a variety of applications, the sensor has been used to measure the RI of binary liquid mixtures. Such measurements can accurately determine the salinity of salt water solutions, and detect the water content of adulterated alcoholic beverages.