Sensitivity-Improved Ultrasonic Sensor for 3D Imaging of Seismic Physical Model Using a Compact Microcavity

Abstract

A sensitivity-improved ultrasonic sensor is proposed and demonstrated experimentally in this present study. The device is comprised only a fiber-optic microcavity that is formed by discharging a short section of hollow core fiber (HCF). The key to ensuring the success of the sensor relies on the preprocessing of hydrogen loading for HCF. When discharging the HCF, the hydrogen is heated up during the formation of the air bubble, which enlarges the bubble diameter, smoothens its surfaces simultaneously and decreases Young’s modulus of the material of the bubble. Ultimately, this results in the probe being highly sensitive to ultrasound with a SNR of 69.28 dB. Once the compact air cavity is formed between the end face of the leading-in fiber and the top wall of the bubble, a well-defined interference spectrum is achieved based on the Fabry–Perot interference. By using spectral side-band filtering technology, we detect the ultrasonic waves reflected by the seismic physical model (SMF) and then reconstruct its three-dimensional image.

Robotic Localization Based on Planar Cable Robot and Hall Sensor Array Applied to Magnetic Capsule Endoscope

“…However, it is expensive and difficult to detect when certain markers are hidden by obstacles such as inside the human body. The ultrasonic system requires a separate system to transmit ultrasonic waves from the target that sensors can detect [ 14 ]. In addition, valid results can only be obtained if the distance between the target and the sensor is above a particular level filled with water or gel.…”

A POSHE-Based Optimum Clip-Limit Contrast Enhancement Method for Ultrasonic Logging Images

“…In the past decades, piezoceramic transducers with the unique capacity of actuating and sensing in a wide-frequency band [ 1 , 2 , 3 , 4 , 5 ], play important roles in ultrasonic techniques, enabling structural health monitoring (SHM) [ 6 , 7 , 8 , 9 ] and nondestructive testing (NDT) [ 10 , 11 , 12 , 13 ] in many fields [ 14 , 15 , 16 , 17 ], and one of them is oil and gas exploration [ 18 , 19 , 20 ]. Piezoceramic transducers are often used to generate and detect ultrasonic waves [ 21 , 22 , 23 , 24 ] that travel through different mediums with reflection and refraction, based on which images of mediums can be obtained [ 25 , 26 , 27 , 28 , 29 , 30 ], and this practice is commonly used in well logging [ 31 , 32 , 33 ]. In the process of ultrasonic imaging logging, acoustic imaging instruments use a rotating piezoceramic transducer to emit and receive ultrasonic pulses traveling through borehole fluid.…”