This invention discloses a
highly sensitive detection device and method for immersion-type ultrasonic
signal detection in liquids. The invention provides a
circular diaphragm with concentric corrugations and a center-thinned structure, and uses this diaphragm as a reflective surface of an optical interference cavity to construct a
highly sensitive detection device for immersion-type ultrasonic
signal detection in liquids. The diaphragm, used to sense ultrasonic signals, has identical concentric corrugations and a center-thinned structure on both sides, enabling the diaphragm to achieve higher mechanical sensitivity without significantly reducing its
natural frequency. The concentric corrugations effectively release initial
residual stress introduced during
processing and packaging, reducing surface warping and
baseline drift. Simultaneously, a replaceable
acoustic membrane is constructed in front of the diaphragm, achieving high sound transmission and anti-
contamination under long-term immersion in liquid conditions. This detection device can be directly placed in the liquid for detection, improving the sensitivity of ultrasonic
signal detection while maintaining a wide frequency range, preventing
contamination of the detection element, and ensuring the long-term stability of the detection device.