High-sensitivity compact ultrasonic detector based on a pi-phase-shifted fiber Bragg grating
High-sensitivity compact ultrasonic detector based on a pi-phase-shifted fiber Bragg grating
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DOI：
10.1364/ol.36.001833
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发表时间：
2011-05-15
期刊：
影响因子：
3.6
通讯作者：
Ntziachristos, Vasilis
中科院分区：
文献类型：
--
作者：
Rosenthal, Amir;Razansky, Daniel;Ntziachristos, Vasilis
研制了一种基于π相移光纤光栅的高灵敏度小型水听器，用于宽带超声声场的测量。该光栅具有尖锐的谐振，其中心波长是压敏的。谐振由连续波（CW）激光器监测，以测量光栅内的超声引起的压力变化。与标准光纤传感器相比，谐振的高精细度（这是传感器高灵敏度的原因）与长传播长度无关。相移周围的光局部化将传感器的有效尺寸减小到光栅的有效尺寸以下，并且与谐振光谱宽度成反比。在我们的系统中，有效传感器长度为270 μ m，压力灵敏度为440 Pa，有效带宽为10 MHz。这种性能使我们的设计有吸引力的医学成像应用，如光声层析成像，其中需要紧凑，灵敏，宽带声探测器。(C)2011年美国光学学会
A highly sensitive compact hydrophone, based on a pi-phase-shifted fiber Bragg grating, has been developed for the measurement of wideband ultrasonic fields. The grating exhibits a sharp resonance, whose centroid wavelength is pressure sensitive. The resonance is monitored by a continuous-wave (CW) laser to measure ultrasound-induced pressure variations within the grating. In contrast to standard fiber sensors, the high finesse of the resonance-which is the reason for the sensor's high sensitivity-is not associated with a long propagation length. Light localization around the phase shift reduces the effective size of the sensor below that of the grating and is scaled inversely with the resonance spectral width. In our system, an effective sensor length of 270 mu m, pressure sensitivity of 440 Pa, and effective bandwidth of 10MHz were achieved. This performance makes our design attractive for medical imaging applications, such as optoacoustic tomography, in which compact, sensitive, and wideband acoustic detectors are required. (C) 2011 Optical Society of America