Adaptive illumination light source for online machine vision inspection of tin steel strips

The different reflection characteristics of the surface of tin steel strips and the different speeds of the tinning line demand an adaptive illumination light source for online machine vision inspection. This light source can be integrated with a time delay integration charge-coupled device （TDI CCD ） to capture the images of moving objects and facilitate inspection of the surface quality of tin steel strips. On-site application show the effectiveness of the TDI camera with the adaptive illumination light source in detecting the surface defects on tin steel strips of three different materials and with different tin coating weights.

Woofer–tweeter adaptive optical structured illumination microscopy

A woofer–tweeter adaptive optical structured illumination microscope(AOSIM) is presented. By combining a low-spatial-frequency large-stroke deformable mirror(woofer) with a high-spatial-frequency low-stroke deformable mirror(tweeter), we are able to remove both large-amplitude and high-order aberrations. In addition, using the structured illumination method, as compared to widefield microscopy, the AOSIM can accomplish highresolution imaging and possesses better sectioning capability. The AOSIM was tested by correcting a large aberration from a trial lens in the conjugate plane of the microscope objective aperture. The experimental results show that the AOSIM has a point spread function with an FWHM that is 140 nm wide(using a water immersion objective lens with NA=1.1) after correcting a large aberration(5.9 μm peak-to-valley wavefront error with 2.05 μm RMS aberration). After structured light illumination is applied, the results show that we are able to resolve two beads that are separated by 145 nm, 1.62× below the diffraction limit of 235 nm. Furthermore, we demonstrate the application of the AOSIM in the field of bioimaging. The sample under investigation was a green-fluorescentprotein-labeled Drosophila embryo. The aberrations from the refractive index mismatch between the microscope objective, the immersion fluid, the cover slip, and the sample itself are well corrected. Using AOSIM we were able to increase the SNR for our Drosophila embryo sample by 5×.