Chromatic confocal microscopy to rapidly reveal nanoscale surface/interface topography by position-sensitive detection

Abstract

This paper presents a confocal microscope for the rapid and noninvasive capture of three-dimensional (3D) images showing the surface/interface topography in a far-field configuration. The proposed microscope features a nanoscale optical ruler capable of performing fast depth measurements based on the chromatic aberration of microscope objectives. A diffraction grating and a position-sensitive detector were used to extract the spectral shift, which directly maps the height of the surface with a nanoscale resolution. Because neither the mechanical scanning nor the spectrometer, which limit the speed of 3D imaging, are needed in the axial direction, full 3D surface topography images with nanoscale depth resolution can be acquired rapidly using the nanoscale optical ruler in conjunction with 2D lateral beam scanning. The presented technique overcomes the limitation of the detection speed of conventional chromatic confocal microscopy. In experiments, the 3D static and dynamic nanoscale surface profiles of several representative optoelectronic and electronic devices were demonstrated. This fast and non-invasive approach with nanoscale depth resolution to the measurement of topography images has considerable promise in academic research and industrial applications.

Surface/Interface Engineering for Constructing Advanced Nanostructured Light-Emitting Diodes with Improved Performance: A Brief Review

“…The analysis of surface interface properties mainly includes surface composition, surface morphology, surface structure, and surface energy state. The main characterization methods used in the experiment and the feedback information are shown in Table 1 [27][28][29][30][31]. Through these characterization methods, we can have a deep and comprehensive understanding of the surface or interface properties of nanomaterials and devices, which provide beneficial help for the further utilization of the surface/interface properties.…”

Investigation and Improvement of Thermal Stability of a Chromatic Confocal Probe with a Mode-Locked Femtosecond Laser Source

“…In responding to the background described above, several types of chromatic confocal probes employing a super-continuum light source, which has a higher light intensity, better spatial coherence, and a wider spectral range, have been developed so far [17][18][19][20]. In addition, optical configurations with various dual-detector setups have been proposed to obtain axial responses in a better sensitivity [21][22][23][24]. The author's group has also proposed a chromatic confocal probe with a new dual-detector setup and a mode-locked femtosecond laser source [24].…”