To obtain high-quality 3D shape for forensic science, we developed a new automated 3D scanning system based on digital fringe projection (DFP) techniques. The system reconstructs two million 3D point cloud data pixel by pixel with color and visualizes the 3D result on the screen within half a second. To capture objects in an environment exposed to low signal-to-noise ratio (SNR), we have applied high-dynamic-range imaging algorithms. With two different capturing modes, users can observe a specific region in more detail through the built-in graphic user interface (GUI): high resolution (400 dpi) for a small field of view or low resolution (140 dpi) for a large field of view. Also, users can easily save the 3D result into the portable storage and compare the data with others in the system.

This paper presents a calibration method for an extended-depth-of-field (EDOF) microscopic structured light system using a calibration target with black circles. The method first extends the DOF by the focal sweep technique to achieve a sufficient measurement range. Then, a computational framework is proposed to resolve the phase error problem caused by the black circles. Experimental results indicate that the proposed method works well in microscopic 3D shape measurement.

This paper proposes a single-camera line-scan hyperspectral four-dimensional imaging technique, which can simultaneously retrieve accurate 3D geometrical information and high-resolution hyperspectral information. The system contains a camera attached to a line spectrograph, a video projector, and a linear guideway. Then the mathematical model for line-scan fringe projection profilometry as well as the 3D reconstruction and spectral calibration methods are investigated. The system can simultaneously achieve high spectral resolution (2.8 nm) and geometric measurement accuracy (0.0895 mm). Test cases will demonstrate that the system can obtain rich spectral and surface topographical information and has potential application in the food industry.

Recently, researchers have found that the power of deep learning can be leveraged to perform high quality 3D shape measurement by directly learning from a single-shot fringe image. However, such end-to-end fringe-to-depth learning has limited flexibility given that its trained deep neural network can only be used for patterns with a certain frequency. This research proposes a phase-to-phase learning approach to address such limitation. By establishing a phase-to-phase training network from phase obtained from Fourier transform to phase obtained from phase shifting, this proposed network can be flexibly applied to measurements with fringe images of different pattern frequencies.

The OptiCentric® product family is the internationally well-established standard for optical centration testing as well as cementing and bonding of lens assemblies. In this presentation we would like to take a closer look at the recently improved OptiCentric® IR series. With a complete redevelopment, driven by the demand for higher accuracy and improved functionality, TRIOPTICS can now provide centration testing with an unprecedented measurement accuracy of ≤0.25 µm for both the MWIR and LWIR range. We would like to welcome you and present in detail, how the OptiCentric® IR can help you optimize your IR lens assembly.

Accurate measurement of the optical constants (n,k) requires an absorptive (i.e. transmission) and dispersive (i.e. reflectance) measurement. Ellipsometry is the gold standard for such measurements, particularly on opaque samples where typical techniques fail to provide an absorptive spectrum. However, an alternative to ellipsometry is needed for microscopy because of the inherent range of angles and planes of incidence when focusing to a small spot. Here we present early images from our complex far-field spectroscopic infrared microscope. An asymmetric interferometer is used to directly measure the infrared reflectance amplitude and absolute phase shift. The complex optical constants can then be extracted without the large uncertainty that arises with a reflectance amplitude measurement alone. Modern QCL sources provide sufficient infrared intensity to realize a type-2 scanning microscope, to achieve a resolution of λ/4 N.A., twice the traditional Abbe limit.

Portable spectrometers are only useful if they provide reliable in-field results. Variable temperature, atmospheric pressure, humidity, dust, vibration, and contaminants threaten their performance. Ruggedized devices resist environmental challenges, but gain weight, power consumption, and cost. The ideal portable instrument weighs little, uses little power, and is calibrated under use conditions, not laboratory conditions. One way to accomplish this is with single use diffraction gratings. Since cuvettes are typically also single use to prevent cross-contamination, why not put them together? We describe diffraction grating/cuvette combinations and explain their fabrication, dispersion properties, and related instrument designs, with expected assets and limitations.