Author Affiliations
Abstract
1 Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing 100871, China
2 National Biomedical Imaging Center, Peking University, Beijing 100871, China
We present a novel noncontact ultrasound (US) and photoacoustic imaging (PAI) system, overcoming the limitations of traditional coupling media. Using a long coherent length laser, we employ a homodyne free-space Mach–Zehnder setup with zero-crossing triggering, achieving a noise equivalent pressure of 703 Pa at 5 MHz and a -6 dB bandwidth of 1 to 8.54 MHz. We address the phase uncertainty inherent in the homodyne method. Scanning the noncontact US probe enables photoacoustic computed tomography (PACT). Phantom studies demonstrate imaging performance and system stability, underscoring the potential of our system for noncontact US sensing and PAI.
noncontact ultrasound sensing photoacoustic imaging Mach–Zehnder interferometer Chinese Optics Letters
2024, 22(3): 031702
Author Affiliations
Abstract
Chongqing Municipal Level Key Laboratory of Photoelectronic Information Sensing & Transmitting Technology, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China
To optimize the optical fiber temperature sensor employing the deep-grooved process, a novel scheme was proposed. Fabricated by the promising CO2 laser irradiation system based on the two-dimensional scanning motorized stage with high precision, the novel deep-grooved optical fiber temperature sensor was obtained with its temperature sensitivity of the transmission attenuation –0.107 dB/℃, which was 18.086 times higher than the optical fiber sensor with the normal depth of grooves while other parameters remained unchanged. The principal research and experimental testing showed that the designed temperature sensor measurement unit had the ability of high sensitivity in transmission attenuation and insensitivity to the wavelength, which offers possible applications in engineering.
OFTS temperature sensitivity transmission attenuation deep-grooved process Photonic Sensors
2015, 5(1): 6–11
