A broadband microstrip-to-waveguide end-wall probe transition using a semicircular loop is proposed in this letter. The simulated 20-dB fractional bandwidth for this transition is 48.3% which could cover the whole Ka-band. Then, a compact broadband waveguide termination is developed by combination of this microstrip-to-waveguide transition and a 50 Ω microstrip termination. To reduce parasitic effects, the microstrip termination is grounded by a microstrip radial stub. The fabricated waveguide termination shows a compact size and has a return loss better than 16.6 dB from 26 to 40.8 GHz.

Optical projection tomography (OPT) is the direct optical equivalent of X-ray computed tomography (CT). To obtain a larger depth of field, traditional OPT usually decreases the numerical aperture (NA) of the objective lens to decrease the resolution of the image. So, there is a trade-off between sample size and resolution. Commercial microfluidic systems can observe a sample in flow mode. In this paper, an OPT instrument is constructed to observe samples. The OPT instrument is combined with commercial microfluidic systems to obtain a three-dimensional and time (3D + T)/four-dimensional (4D) video of the sample. “Focal plane scanning” is also used to increase the images’ depth of field. A series of two-dimensional (2D) images in different focal planes was observed and compared with images simulated using our program. Our work dynamically monitors 3D OPT images. Commercial microfluidic systems simulate blood flow, which has potential application in blood monitoring and intelligent drug delivery platforms. We design an OPT adaptor to perform OPT on a commercial wide-field inverted microscope (Olympusix81). Images in different focal planes are observed and analyzed. Using a commercial microfluidic system, a video is also acquired to record motion pictures of samples at different flow rates. To our knowledge, this is the first time an OPT setup has been combined with a microfluidic system.

In this paper, a real-time, dynamic three-dimensional (3D) shape reconstruction scheme based on the Fourier-transform profilometry (FTP) method is achieved with a short-wave infrared (SWIR) indium gallium arsenide (InGaAs) camera for monitoring applications in low illumination environments. A SWIR 3D shape reconstruction system is built for generating and acquiring the SWIR two-dimensional (2D) fringe pattern of the target. The depth information of the target is reconstructed by employing an improved FTP method, which has the advantages of high reconstruction accuracy and speed. The maximum error in depth for static 3D shape reconstruction is 1.15 mm for a plastic model with a maximum depth of 36 mm. Meanwhile, a real-time 3D shape reconstruction with a frame rate of 25 Hz can be realized by this system, which has great application prospects in real-time dynamic 3D shape reconstruction, such as low illumination monitoring. In addition, for real-time dynamic 3D shape reconstruction, without considering the edge areas, the maximum error in depth among all frames is 1.42 mm for a hemisphere with a depth of 35 mm, and the maximum error of the average of all frames in depth is 0.52 mm.

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A real-time high dynamic range (HDR) imaging and display method based on correlated double sampling is proposed for short-wave infrared (SWIR) cameras in order to effectively improve its range of brightness and contrast, as well as to obtain more image details. The method utilizes the correlated double sampling technique of the SWIR detector to extend the 14-bit raw image into a 16-bit HDR image and achieve 4 times the HDR imaging. Subsequently, a dynamic range compression process, including logarithmic mapping and histogram equalization, is performed for the 16-bit HDR image to be mapped to an 8-bit display. Finally, the experimental results show that the method can enrich the details of SWIR images under the premise of ensuring real-time imaging.