We show for the first time that a single ultrasonic imaging fibre is capable of simultaneously accessing 3D spatial information and mechanical properties from microscopic objects. The novel measurement system consists of two ultrafast lasers that excite and detect high-frequency ultrasound from a nano-transducer that was fabricated onto the tip of a single-mode optical fibre. A signal processing technique was also developed to extract nanometric in-depth spatial measurements from GHz frequency acoustic waves, while still allowing Brillouin spectroscopy in the frequency domain. Label-free and non-contact imaging performance was demonstrated on various polymer microstructures. This singular device is equipped with optical lateral resolution, 2.5 μm, and a depth-profiling precision of 45 nm provided by acoustics. The endoscopic potential for this device is exhibited by extrapolating the single fibre to tens of thousands of fibres in an imaging bundle. Such a device catalyses future phonon endomicroscopy technology that brings the prospect of label-free in vivo histology within reach.

我们首次展示了单个超声成像纤维能够同时从微观物体访问3D空间信息和机械性能。这种新颖的测量系统由两个超快激光器组成，它们激发并检测来自纳米换能器的高频超声，该纳米换能器被制造在单模光纤尖端上。还开发了一种信号处理技术来从GHz频率声波中提取纳米级深度空间测量值，同时仍允许在频域中进行布里渊光谱分析。在各种聚合物微结构上证明了无标签和非接触式成像性能。这种单一的设备具有光学横向分辨率，2.5μm和声学特性，可提供45 nm的深度轮廓精度。通过将单个光纤外推到成像束中的数以万计的光纤中，可以展现该设备的内窥镜潜能。这种设备催化了未来的声子内窥镜技术，使无标签体内组织学的前景触手可及。