We have constructed fiber-optic sensors to measure temperature and strain by combining the properties of fiber Bragg gratings with the fluorescent lifetimes of various doped fibers. Sensors have been made with the fiber Bragg grating written directly into the doped fiber to ensure the collocation of the strain and temperature measurement points. Results are compared with those obtained previous...

This study presents the modelling, simulation, and characterization of the Fiber Bragg grating (FBG) on maximum reflectivity, bandwidth, the effect of applied strain to the wavelength shift, ŽB and sensitivity of the wavelength shift with strain for optical sensing system. In this study, a commercial FBG with the center wavelength of 1550nm is used in order to measure the spectral response of F...

We describe the characterization of the temperature and strain responses of fiber Bragg grating sensors by use of an interferometric interrogation technique to provide an absolute measurement of the grating wavelength. The fiber Bragg grating temperature response was found to be nonlinear over the temperature range -70 degrees C to 80 degrees C. The nonlinearity was observed to be a quadratic f...

This paper deals with mathematical modeling, design and application of Fiber Bragg Grating as temperature sensor .In this paper we used the MATLAB and filter characteristics simulation software as a tool for simulation results. The fabrication of Fiber Bragg Grating, their characteristics and fundamental properties are described. The reflectivity of FBG is described using simulation results. Th...

Being one of the most proven fiber optic devices, the fiber Bragg grating has developed continually to extend its applications, particularly in extreme environments. Accompanying the growth of Type-IIa Bragg gratings in some active fibers, a new resonance appears at the shorter wavelength. This new type of grating was named "secondary Bragg grating" (SBG). This paper describes the formation and...

It is well known that chirped (aperiodic) refractiveindex Bragg gratings can be used for compensating for the dispersion of optical fiber waveguides.' When used in reflection mode (in contrast to transmission mode), such Bragg gratings exhibit large dispersion. As well, the sign of the dispersion in reflection mode is easily controlled. Together these two characteristics suggest the use of chir...

Fiber Bragg grating is inscribed on microfiber with femtosecond laser pulses irradiation. The microfiber is fabricated by stretching a section of single mode fiber over a flame. Periodic grooves are carved on the microfiber by the laser as have been observed experimentally. The microfiber Bragg grating is demonstrated for temperature and strain sensing, and the strain sensitivity is improved wi...

This paper demonstrates, for the first time to our best knowledge, the application of a tunable external-cavity fiber Bragg grating diode laser in spectroscopic chemical sensing. A tunable fiber Bragg grating external-cavity semiconductor laser is demonstrated with over 10 nm of tuning range. A piezo-actuator was implemented to stretch the grating for rapid wavelength tuning of the laser. The a...

We proposed and experimentally demonstrated a highly sensitive salinity sensor using a polyimide-coated Hi-Bi photonic crystal fiber Sagnac interferometer based on the coating swelling induced radial pressure. This is the first time to exploit fiber coating induced pressure effect for salinity sensing. The achieved salinity sensitivity is 0.742 nm/(mol/L), which is 45 times more sensitive than ...

Application of the Transverse Chirped Bragg Grating (TCBG a reflecting volume Bragg grating with continuously variable resonant wavelength across the aperture) for the narrowband tunable ring-cavity fiber laser is presented. The main advantage of the use of TCBG is that its linear translation allows continuous tuning of emission wavelength within 5-10 nm band. Yb doped fiber laser operating in ...