It is well known that fibers improve the performance of cementitious composites by acting as bridging ligaments in cracks. Such bridging behavior is often studied through fiber pullout tests. The relation between the pullout force vs. slip end displacement is characteristic of the fiber-matrix interface. However, such a relation varies significantly with the fiber inclination angle. In the curr...

We review our recent progress in the characterization of the embedding of rare-earth elements in nanometer-scale particles or phase-separated glassy regions within the core of silicabased optical fibres, and discuss future directions. OCIS codes: (060.2290) Fiber materials; (060.2410) Fibers, erbium; (060.2320) Fiber optics amplifiers and oscillators; (060.3510) Lasers, fiber; (160.5690) Rare-e...

This paper describes a proposal and successful demonstration of a dual wavelength all-fiber passively Q-switched erbium-doped fiber ring laser. The Q-switch operation was realized by using a nonlinear loop mirror that incorporated an unbalanced dispersion-decreasing taper fiber to act as a saturable absorber without additional elements. This setup enabled a fiber ring laser to achieve a perform...

The buckling and postbuckling behaviors of a composite beam with single delamination are investigated. A three-dimensional finite element model using the commercial code ANSYS is employed for this purpose. The finite elements analyses have been performed using a linear buckling model based on the solution of the eigenvalues problem, and a non-linear one based on an incremental-iterative method....

Optical fiber communication has brought us a new Internet society. In Japan, FTTH (Fiber to the Home) networks, in which optical fibers are installed directly to users’ homes, have been so popular that the number of contractors for FTTH service has exceeded fifteen millions as of May 2010. “Optical fiber,” “light source,” and “photo detector” are said to be three key elements of optical fiber c...

A functionally graded (FG) material system is employed to make fiber use more efficient in a fiber reinforced cement composite (FRCC). This preliminary study demonstrates beam elements that were functionally graded fiber reinforced cement composite (FGFRCC) with four layers, each with a different fiber volume ratio. Fiber volume ratio was graded in accordance with its potential contribution to ...

Optical fiber sensing has been extensively studied in various areas such as aging deterioration measurement of constructed building, seismic measurement, environmental measurement. Optical fiber sensing systems are classified into two configurations. One consists of an optical source, an optical fiber transmission line, and sensing elements. The other consists of a fiber lasing system including...

This Letter presents distributed Bragg reflector (DBR) fiber lasers for high-temperature operation at 750°C. Thermally regenerated fiber gratings were used as the feedback elements to construct an erbium-doped DBR fiber laser. The output power of the fiber laser can reach 1 mW at all operating temperatures. The output power fluctuation tested at 750°C was 1.06% over a period of 7 hours. The the...