A fiber-optic temperature and pressure sensor array for ocean observation is built and studied experimentally. The sensor array consists of 4 subarrays. Each sensor subarray is composed of a certain number of FBG temperature sensors and FBG pressure sensors which are connected in a single optical fiber. The wavelength scanning and time division multiplexing techniques are combined to demodulate the FBG wavelengths of sensor array. The experimental results show that the wavelengths of FBGs in different subarrays can be demodulated and all the sensors can measure the temperature or pressure with high accuracy. The fiber-optic temperature and pressure sensor array and the demodulation method have great potential application in acquirement of the vertical profile of temperature in seawater.
A novel compact temperature sensor based on a fiber loop mirror (FLM) combined with an alcohol-filled highlybirefringent
photonic crystal fiber (HiBi-PCF) is proposed and experimentally demonstrated. The output of the FLM is
an interference spectrum with many dips, of which the resonant wavelengths are quite sensitive to temperature because
the interference of the FLM is sensitive to the optical path difference due to the refractive index change of the filled
alcohol. Experimental results show that the temperature sensitivity reaches up to 5.42nm/°C for a 6.3cm long alcoholfilled
PCF used in the FLM.
A two-dimensional (2-D) inclinometer based on three optical fiber Bragg gratings (FBGs) is proposed and demonstrated.
Preliminary experiments show that a high measurement sensitivity of 192 pm/° and resolution of 0.005° can be achieved
and this sensor is proved to be insensitive to temperature.
A novel fiber Bragg grating (FBG) inclinometer is proposed to detect the magnitude as well as the direction of a twodimensional
(2-D) inclination by using three FBGs. Preliminary results show that this sensor is insensitive to temperature
and a high accuracy and high resolution can be achieved.