A High-Resolution Measurement Method for Inner and Outer 3D Surface Profiles of Laser Fusion Targets Using a Laser Differential Confocal–Atomic Force Probe Technique

The high-resolution and nondestructive co-reference measurement of the inner and outer threedimensional(3D)surface profiles of laser fusion targets is difficult to achieve.In this study,we propose a laser differential confocal(LDC)–atomic force probe(AFP)method to measure the inner and outer 3D surface profiles of laser fusion targets at a high resolution.This method utilizes the LDC method to detect the deflection of the AFP and exploits the high spatial resolution of the AFP to enhance the spatial resolution of the outer profile measurement.Nondestructive and co-reference measurements of the inner profile of a target were achieved using the tomographic characteristics of the LDC method.Furthermore,by combining multiple repositionings of the target using a horizontal slewing shaft,the inner and outer 3D surface profiles of the target were obtained,along with a power spectrum assessment of the entire surface.The experimental results revealed that the respective axial and lateral resolutions of the outer profile measurement were 0.5 and 1.3 nm,while the respective axial and lateral resolutions of the inner profile measurement were 2.0 nm and approximately 400.0 nm.The repeatabilities of the rootmean-square deviation measurements for the outer and inner profiles of the target were 2.6 and 2.4 nm,respectively.We believe our study provides a promising method for the high-resolution and nondestructive co-reference measurement of the inner and outer 3D profiles of laser fusion targets.

Large dynamic range Shack-Hartmann wavefront sensor based on adaptive spot matching

The Shack-Hartmann wavefront sensor(SHWS)is widely used for high-speed,precise,and stable wavefront measurements.However,conventional SHWSs encounter a limitation in that the focused spot from each microlens is restricted to a single microlens,leading to a limited dynamic range.Herein,we propose an adaptive spot matching(ASM)-based SHWS to extend the dynamic range.This approach involves seeking an incident wavefront that best matches the detected spot distribution by employing a Hausdorff-distance-based nearest-distance matching strategy.The ASM-SHWS enables comprehensive spot matching across the entire imaging plane without requiring initial spot correspondences.Furthermore,due to its global matching capability,ASM-SHWS can maintain its capacity even if a portion of the spots are missing.Experiments showed that the ASM-SHWS could measure a high-curvature spherical wavefront with a local slope of 204.97 mrad,despite a 12.5%absence of spots.This value exceeds that of the conventional SHWS by a factor of 14.81.

A high-precision multi-dimensional microspectroscopic technique for morphological and properties analysis of cancer cell

Raman and Brillouin scattering are sensitive approaches to detect chemical composition and mechanical elasticity pathology of cells in cancer development and their medical treatment researches.The application is,however,suffering from the lack of ability to synchronously acquire the scattering signals following three-dimensional(3D)cell morphology with reasonable spatial resolution and signal-to-noise ratio.Herein,we propose a divided-aperture laser differential confocal 3D Geometry-Raman-Brillouin microscopic detection technology,by which reflection,Raman,and Brillouin scattering signals are simultaneously in situ collected in real time with an axial focusing accuracy up to 1 nm,in the height range of 200μm.The divided aperture improves the anti-noise capability of the system,and the noise influence depth of Raman detection reduces by 35.4%,and the Brillouin extinction ratio increases by 22 dB.A high-precision multichannel microspectroscopic system containing these functions is developed,which is utilized to study gastric cancer tissue.As a result,a 25%reduction of collagen concentration,42%increase of DNA substances,17%and 9%decrease in viscosity and elasticity are finely resolved from the 3D mappings.These findings indicate that our system can be a powerful tool to study cancer development new therapies at the sub-cell level.

Synchronous nanoscale topographic and chemical mapping by differential-confocal controlled Raman microscopy

Confocal Raman microscopy is currently used for label-free optical sensing and imaging within the biological,engineering,and physical sciences as well as in industry.However,currently these methods have limitations,including their low spatial resolution and poor focus stability,that restrict the breadth of new applications.This paper now introduces differential-confocal controlled Raman microscopy as a technique that fuses differential confocal microscopy and Raman spectroscopy,enabling the point-to-point collection of three-dimensional nanoscale topographic information with the simultaneous reconstruction of corresponding chemical information.The microscope collects the scattered Raman light together with the Rayleigh light,both as Rayleigh scattered and reflected light(these are normally filtered out in conventional confocal Raman systems).Inherent in the design of the instrument is a significant improvement in the axial focusing resolution of topographical features in the image(to^1 nm),which,when coupled with super-resolution image restoration,gives a lateral resolution of 220 nm.By using differential confocal imaging for controlling the Raman imaging,the system presents a significant enhancement of the focusing and measurement accuracy,precision,and stability(with an antidrift capability),mitigating against both thermal and vibrational artefacts.We also demonstrate an improved scan speed,arising as a consequence of the nonaxial scanning mode.