Fiber-optic sensing is a field that is developing at a fast pace. Novel fiber-optic sensor designs and sensing principles constantly open doors for new opportunities. In this paper, we review a fiber-optic sensing technique developed in our research group called frequency-shifted interferometry (FSI). This technique uses a continuous-wave light source, an optical frequency shifter, and a slow d...

The objective of this paper is to provide a contemporary look at the current state-of-the-art in wireless sensor and fiber optic sensor for structure health monitoring (SHM) applications and discuss issue related to those system and hence, to make the efficient decision that provided the better system thinking. Specially, this paper provides review about structural health monitoring like, bridg...

In this paper, we propose a temperature/thermal sensor that contains a Rhodamine-B sensing membrane. We applied two different sensing methods, namely, fiber-optic pulse width modulation (PWM) and an interdigitated capacitor (IDC)-based temperature sensor to measure the temperature from 5 °C to 100 °C. To the best of our knowledge, the fiber-optic PWM-based temperature sensor is reported for the...

Guided wave detection using different fiber optic sensors and their applications in damage detection for composite laminates were systematically investigated and compared in this paper. Two types of fiber optic sensors, namely fiber Bragg gratings (FBG) and Doppler effect-based fiber optic (FOD) sensors, were addressed and guided wave detection systems were constructed for both types. Guided wa...

Based on the principle of blackbody radiation, sapphire optic fiber temperature sensor has been more widely used in recent years, and its temperature range is between 800 ~ 2000 oC, and the response time is in 10-2 magnitude, and transient temperature measurement can be high precision in harsh environments. Nonlinear constraints on sapphire fiber temperature sensor affect the accuracy and stabi...

The use of a LED fiber-optic sensor to measure displacement and linear thermal expansion is described. It has a sensitivity of about 0.6 mV/mm, a resolution of 1.25 mm, and a dynamic rang of 400 mm for displacement measurements. For thermal expansion, it shows a sensitivity of about 3.5 mV/C, and the experimental linear expansion values are in agreement with those calculated. The reported senso...

A novel fiber-optic bending sensor based upon the propagation of LP21 mode is demonstrated. The sensor, comprised of an S-bend fiber on an elastic film, measures LP21 mode specklegram rotation, which increments linearly with bending angle by the stress-optic effect. The sensor is capable of experimentally achieving a sensitivity as high as 4.13 rad/m(-1). The theoretical analysis of the sensor,...

In this paper, we introduced a new fiber-optic temperature sensor with white light interferometric principle based on Fabry-Perot, which is capable of providing measurement for the temperature of greenhouse. The signal processing of system is that the optical signal wavelength is modulated in the Fabry-Perot cavity and is demodulated during the optical-electricity transform. Compared with a com...

Photonic sensors, signal processors and communication technologies have emerged as viable alternatives to electronics. Fiber optic sensors have advanced to an extent that they can be readily made use of in many applications. The different types of fiber optic sensors, components used in optical fiber sensing, sensor design and analysis, distributed\ multiplexed sensor schemes and the role of in...