The computed tomography imaging spectrometer (CTIS) is a relatively unknown snapshot hyperspectral camera. It utilizes computational imaging approaches to gain the hyperspectral image from a spatio-spectral smeared sensor image. We present a strongly miniaturized system with a dimension of only 36 × 40.5 × 52.8 mm and a diagonal field of view of 29°. We achieve this using a Galilean beam expander and a combination of off-the-shelf lenses, a highly aspherical imaging system from a commercial smartphone, and a 13 MP monochrome smartphone image sensor. The reconstructed hyperspectral image has a spatial resolution of 400 × 300 pixel with 39 spectral channels.
This paper presents optical solitons with the concatenation model having spatio-temporal and chromatic dispersions. This model can advantageously curtail the Internet bottleneck effect. Two integration schemes yield these solitons. By utilizing the multipliers approach, the conservation laws are also derived.
Medical femtosecond laser devices are used in dermatology for non-linear high-resolution imaging to obtain non-invasive and label-free optical skin biopsies (multiphoton tomography) as well as in ophthalmology for refractive corneal surgery and cataract surgery. Applications of commercial certified multiphoton tomographs include early detection of skin cancer within minutes by two-photon autofluorescence imaging of coenzymes and melanin and second harmonic imaging of collagen as well as by testing the efficacy of pharmaceutical and cosmetical products. Goals are (i) to reduce the number of physically taken human skin biopsies in hospitals and research institutions, (ii) to optimize personalized medicine, and (iii) to reduce animal studies in pharmacy. Current diagnostic tools in dermatology include surface microscopy with a dermatoscope and ultrasound but have poor resolution. Optical coherence tomography and confocal reflectance microscopy have better resolution but provide limited information based on changes of the intratissue refractive index. Multiphoton tomography provides the best resolution of all clinical imaging methods and offer functional imaging such as optical metabolic imaging based on autofluorescence lifetime imaging. Goals of femtosecond laser eye treatment are (i) the replacement of mechanical microkeratomes for corneal flap generation, (ii) the replacement of the UV nanosecond excimer laser for stroma removal, and (iii) to replace, in part, the scalpel in the surgery of cataracts and other eye diseases. So far, millions of eye treatments have been conducted around the world. The major disadvantage of current certified medical femtosecond laser devices is the high price compared with the standard mechanical and optical medical devices.
The parameter dynamics of super-sech and super-Gaussian pulses for the perturbed nonlinear Schrödinger’s equation with power-law nonlinearity is obtained in this article. The variational principle successfully recovers this dynamical system. The details of the variational principle with the implementation of the Euler–Lagrange’s equation to the nonlinear Schrödinger’s equation with power-law of nonlinearity described in this paper have not been previously reported.
Line-field Confocal Optical Coherence Tomography (LC-OCT) is an imaging modality based on a combination of time-domain optical coherence tomography and reflectance confocal microscopy. LC-OCT provides three-dimensional images of semi-transparent samples with a spatial resolution of ∼1 μm. The technique is primarily applied to in vivo skin imaging. The image contrast in LC-OCT arises from the backscattering of incident light by the sample microstructures, which is determined by the optical scattering properties of the sample, characterized by the scattering coefficient μs and the scattering anisotropy factor g. In biological tissues, the scattering properties are determined by the organization, structure and refractive indexes of the sample. The measurement of these properties using LC-OCT would therefore allow a quantitative characterization of tissues in vivo. We present a method for extracting the two scattering properties μs and g of tissue-mimicking phantoms from 3D LC-OCT images. The method provides the mean values of μs and g over a lateral field of view of 1.2 mm × 0.5 mm (x × y). It can be applied to monolayered and bilayered samples, where it allows extraction of μs and g of each layer. Our approach is based on a calibration using a phantom with known optical scattering properties and on the application of a theoretical model to the intensity depth profiles acquired by LC-OCT. It was experimentally tested against integrating spheres and collimated transmission measurements for a set of monolayered and bilayered scattering phantoms.
The present study is devoted to investigate the chirped gap solitons with Kudryashov’s law of self-phase modulation having dispersive reflectivity. Thus, the mathematical model consists of coupled nonlinear Schrödinger equation (NLSE) that describes pulse propagation in a medium of fiber Bragg gratings (BGs). To reach an integrable form for this intricate model, the phase-matching condition is applied to derive equivalent equations that are handled analytically. By means of auxiliary equation method which possesses Jacobi elliptic function (JEF) solutions, various forms of soliton solutions are extracted when the modulus of JEF approaches 1. The generated chirped gap solitons have different types of structures such as bright, dark, singular, W-shaped, kink, anti-kink and Kink-dark solitons. Further to this, two soliton waves namely chirped bright quasi-soliton and chirped dark quasi-soliton are also created. The dynamic behaviors of chirped gap solitons are illustrated in addition to their corresponding chirp. It is noticed that self-phase modulation and dispersive reflectivity have remarkable influences on the pulse propagation. These detailed results may enhance the engineering applications related to the field of fiber BGs.
Recently, Kumar Gerry et al. [Phys. Rev. A 90, 033427 (2014) https://doi.org/10.1103/PhysRevA.90.033427] studied the coherence control in a six-level atom through solving the Schrödinger equation in the field-interaction representation. In this manuscript, we investigate the interaction between a six-level atomic system (SLAS) and a single-mode field initially prepared in a squeezed coherent state. We extend the Jeans–Cummings model to describe the interaction between the atom and the squeezed field (SF) and the system dynamics. We examine the time evolution of the atomic coherence, non-local correlation, statistical properties within the bipartite system in the presence and absence intensity-dependent coupling (I-DC) for different squeezing regimes of the field.
Metal parts with highly dynamic areas often appear in industrial production measurements. However, if the traditional fringe projection technique is used to project fringe onto the surface of these metal parts, the light energy will be excessively concentrated and the image will be saturated, resulting thus in the loss of fringe information. To effectively address the high reflectivity problem of the object under test in fringe projection, background normalized Fourier transform contouring was combined with adaptive fringe projection in this work and a new method for performing highly dynamic 3D measurements was proposed. To reduce the number of the acquired images by the camera, a monochromatic fringe of different frequencies was put into the RGB channel to make color composite fringe, and then a color camera was used to acquire the deformed color composite fringe map. The images acquired by the color camera were then separated into three channels to obtain three deformed stripe maps. The crosstalk was also removed from these three images, and the 3D shape of the object was reconstructed by carrying out Fourier transform contouring with background normalization. From our experiments, it was demonstrated that the root mean square error of the proposed method can reach 0.191 mm, whereas, unlike the traditional methods, the developed method requires four images.
The application of starlight refraction navigation to spacecraft and space weapons is a significant development direction. Observing enough refracted stars for the star sensor in a strong limb background is an urgent problem. The all-day optical system parameters are analyzed based on the star detection requirement and navigation accuracy. Combined with primary aberration theory, the prime-focus catadioptric optical system is selected to meet the design requirements of a wide field of view (FOV) and tight structure. An H-band (1.52 μm–1.78 μm) star sensor is designed with an FOV of 6°, a focal length of 831 mm, an effective aperture of 253 mm, and a relative distortion of 0.03%. The energy concentration of the star point is 85% within 30 μm, and the maximum lateral chromatic aberration is 2.9 μm, which meets the imaging requirements. Furthermore, a baffle is designed to avoid the influence of direct sunlight on stellar imaging. The proposed method can provide a theoretical foundation and technical support for the optical design of the refraction star navigation.