Robin Martin, Guis Ruben, Arabul Mustafa Umit, Zhou Zili, Pandey Nitesh, Verbiest Gerard J
Department of Precision and Microsystems Engineering, Delft University of Technology, Mekelweg 2, Delft, 2628CD, Netherlands.
ASML Netherlands B.V., De Run 6501, Veldhoven, 5504DR, Netherlands.
Photoacoustics. 2023 Mar 4;30:100470. doi: 10.1016/j.pacs.2023.100470. eCollection 2023 Apr.
Conoscopic interferometry is a promising detection technique for ultrafast acoustics. By focusing a probe beam through a birefringent crystal before passing it through a polarizer, conoscopic interferences sculpt the spatial profile of the beam. The use of these patterns for acoustic wave detection revealed a higher detection sensitivity over existing techniques, such as reflectometry and beam distortion detection. However, the physical origin of the increased sensitivity is unknown. In this work, we present a model, describing the sensitivity behavior of conoscopic interferometry with respect to the quarter-wave plate orientation and the diaphragm aperture, which is validated experimentally. Using the model, we optimize the detection sensitivity of conoscopic interferometry. We obtain a maximal sensitivity of detection when placing the diaphragm edge on the dark fringes of the conoscopic interference patterns. In the configurations studied in this work, conoscopic interferometry can be 18 dB more sensitive to acoustic waves than beam distortion detection.
锥光干涉测量法是一种很有前景的超快声学检测技术。通过在探测光束穿过偏振器之前使其聚焦通过双折射晶体，锥光干涉会塑造光束的空间轮廓。利用这些图案进行声波检测显示出比现有技术（如反射测量法和光束畸变检测）更高的检测灵敏度。然而，灵敏度提高的物理根源尚不清楚。在这项工作中，我们提出了一个模型，该模型描述了锥光干涉测量法相对于四分之一波片取向和光阑孔径的灵敏度行为，并通过实验进行了验证。利用该模型，我们优化了锥光干涉测量法的检测灵敏度。当将光阑边缘置于锥光干涉图案的暗条纹上时，我们获得了最大检测灵敏度。在本工作所研究的配置中，锥光干涉测量法对声波的灵敏度可比光束畸变检测高18分贝。
