Abstract
An optoacoustic probe including an optical fiber and a Fabry-Perot interfering structure is provided. The optical fiber includes a center core, a concentric core and a cladding layer. The optical fiber has an end surface. A refractive index of the center core is larger than a refractive index of the concentric core, and a refractive index of the concentric core is larger than a refractive index of the cladding layer. The Fabry-Perot interfering structure is disposed on the end surface and covers a portion of the center core exposed at the end surface. An optoacoustic sensing method including following steps is provided. A pulse laser is transmitted via the concentric core to an object to be sensed. The Fabry-Perot interfering structure receives an ultrasound generated from the object excited by the pulse laser and modulates a return light transmitted via the center core with using the ultrasound into a return modulated light. Information of the object can be obtained by receiving and analyzing the return modulated light transmitted via the center core. An optoacoustic sensing system is also provided.