Kerrrowland8631

Many methods have been proposed to reconstruct the moving object based on phase shifting profilometry. Quality reconstruction results can be achieved when a single moving object or multiple objects with same movement are measured. However, errors will be introduced when multiple objects with individual movements are reconstructed. This paper proposes an automated method to track and reconstruct the multiple objects with individual movement. First, the objects are identified automatically and their bounding boxes are obtained. Second, with the identified objects' images before movement, the objects are tracked by the KCF algorithm in the successive fringe pattern after movement. Third, the SIFT method is applied on the tracked object images and the objects' movement is described individually by the rotation matrix and translation vector. Finally, the multiple objects are reconstructed based on the different movement information. Experiments are presented to verify the effectiveness.We demonstrate coupling to and control over the broadening and dispersion of a mid-infrared leaky mode, known as the Berreman mode, in samples with different dielectric environments. We fabricate subwavelength films of AlN, a mid-infrared epsilon-near-zero material that supports the Berreman mode, on materials with a weakly negative permittivity, strongly negative permittivity, and positive permittivity. Additionally, we incorporate ultra-thin AlN layers into a GaN/AlN heterostructure, engineering the dielectric environment above and below the AlN. In each of the samples, coupling to the Berreman mode is observed in angle-dependent reflection measurements at wavelengths near the longitudinal optical phonon energy. The measured dispersion of the Berreman mode agrees well with numerical modes. Differences in the dispersion and broadening for the different materials is quantified, including a 13 cm-1 red-shift in the energy of the Berreman mode for the heterostructure sample.A novel noise-suppressing and lock-free interferometer is proposed and experimentally demonstrated in the study of the quantum non-destructive (QND) interaction of cold atoms. A QND measurement based on far-off resonant dispersive probing is usually carried out by a Mach-Zehnder type interferometer. It is an experimental challenge in its own right to reduce the classical noise, such as acoustic noise, phase noise and amplitude noise of lasers, and to lock the interferometer at the white-light position that corresponds to a nearly zero path-length difference. Here, we report an interferometer with an inserted acousto-optic modulator (AOM). It is noise immune and lock-free in principle. The experiments show that the new interferometer is able to measure cold atoms for more than 30 minutes and reduce the phase noise by about 30 dB.In this paper, we present a study of observation of phase error of a volume holographic storage disc during the reading process when the disc is rotated or displaced in the theoretical calculation and the corresponding experiment. This additional phase error will dramatically decrease the bit error rate of a phase-only signal, even applying double-frequency shearing interferometry to retrieve the stored phase signal. Then we propose a novel approach to solve the problem. The stored signal is pre-processed by phase integral along the shearing direction so that applying the integral process to decode the phase signal is not necessary in the readout process. The proposed approach effectively reduces the error in phase retrieval and will be useful when applying double-frequency shearing interferometry in the readout process for volume holographic storage.Photonic microwave generation of high-power pulsed signals in the X-, Ku- and K-band using charge-compensated MUTC photodiodes is demonstrated. https://www.selleckchem.com/products/bgb-3245-brimarafenib.html The impulse photoresponse without modulation showed a maximum peak voltage of 38.3 V and full-width at half-maximum of 30 ps. High power pulsed microwave signals at 10, 17 and 22 GHz with peak power up to 44.2 dBm (26.3 W), 41.6 dBm (14.5 W) and 40.6 dBm (11.5 W) were achieved, respectively.Adachi proposed a procedure to avoid divergences in optical-constant models by slightly shifting photon energies to complex numbers on the real part of the complex dielectric function, ε1. The imaginary part, ε2, was ignored in that shift and, despite this, the shifted function would also provide ε2 (in addition to ε1) in the limit of real energies. The procedure has been successful to model many materials and material groups, even though it has been applied phenomenologically, i.e., it has not been demonstrated. This research presents a demonstration of the Adachi procedure. The demonstration is based on that ε2 is a piecewise function (i.e., it has more than one functionality), which results in a branch cut in the dielectric function at the real photon energies where ε2 is not null. The Adachi procedure is seen to be equivalent to a recent procedure developed to turn optical models into analytic by integrating the dielectric function with a Lorentzian function. Such equivalence is exemplified on models used by Adachi and on popular piecewise optical models Tauc-Lorentz and Cody-Lorentz-Urbach models.We propose and experimentally demonstrate a novel method to realize an optical vector analyzer (OVA) with a largely increased measurement range based on linearly frequency-modulated (LFM) waveform and a recircuiting frequency shifter (RFS) loop. An optical LFM signal is sent into an RFS loop to extend its frequency range by circulating in the loop. At the output of the RFS, the frequency-extended optical LFM signal is launched into a Mach-Zehnder interferometer (MZI1) with the device under test (DUT) incorporated in one arm and a delay line in the other arm. By beating the optical signals from the MZIs at a pair of balanced photodetectors, low-frequency signals are generated, from which the frequency responses of the DUT can be extracted using post-digital signal processing. To eliminate the unwanted influence from the measurement system, another MZI (MZI2) sharing the delay line arm with the MZI1 is used for system self-calibration. Thanks to the largely extended frequency range of the optical LFM signal with the use of the RFS loop, the measurement range of the OVA is highly increased.