We propose a hyperspectral broadband phase retrieval technique with spectrally varying object and modulation phase masks. The technique is based on a complex domain version of the alternating direction method of multipliers (ADMM) and the Spectral Proximity Operators derived for Gaussian and Poisson intensity observations, which are considered as a sum of separate spectral diffractive patterns. The proximity operators filter noisy observations compromising between noisy intensity observations and their predicted counterparts and retrieve the complex-domain spectral components of the object from these filtered observations. The simulation and physical tests confirm that the broadband hyperspectral phase retrieval in the proposed formulation is resolved.

We show that a single pulse burst fabrication will produce a flatter and smoother profile of axicons milled on sapphire compared to a pulse overlapped fabrication which will result in a damaged and a much rougher surface. The fabrication of large area (sub-1 cm cross-section) micro-optical components in a short period of time (~ 10 min) and with lesser number of processing steps is highly desirable and cost-effective. Our results were achieved with femtosecond laser fabrication technology which has revolutionized the field of manufacturing axicons. This study shows the manufacture of three configurations such as the conventional axicon, a photon sieve axicon (PSA) and a sparse PSA directly milled onto a sapphire substrate. Debris was removed using IsoPropyl alcohol and potassium hydroxide and amorphous sapphire was redeposited under incoherent illumination to test the components for optical viability. A non-linear optical filter was used for cleaning noisy images which were generated by diffractive optical elements.

Multi-Photon Polymerization (MPP), has found application in the field of Tissue Engineering (TE), due to the ability of fabrication of high precision scaffolds that can be used as a cell culture substrate. Of great importance is the Peripheral Nervous System (PNS) Tissue Engineering and Regeneration which shows increasing potential as an alternative to established methods, namely surgery and grafts, that aim to counter PNS-related diseases. A femtosecond fiber laser operating at 780nm (pulse duration:120fs, repetition rate:80MHz) was utilized to fabricate a novel pyramid-shaped scaffold geometry (400μm×400μm×60μm) using an organic/inorganic hybrid material. The scaffolds were used as a substrate for the mono- and co-culture of murine neuronal N2a and glial Schwann (SW10) cells for 7, 14 and 21 days with flat glasses as controls. Comparison between scaffolds and controls revealed cell and neurite directionality that was highly influenced by the presence of scaffold topography vs the random orientation controls exhibited, due to the cell responses to the topographical cues provided. In addition, the co-culture system provided a favorable environment for longer neurite formation after 21 days compared to mono-cultures, showing a 2-fold increase in neurites longer than 40μm (31.4%±5.5% vs 15.4%±5.4% of total neurites respectively), indicating a possible synergistic effect of co-cultures and scaffold topography. These findings suggest the ability to control neurite length and directionality, which are crucial parameters in PNS TE, and could form the basis for the development of an in vitro model for the study of PNS-related diseases.

Mobile phones, laptops, computers, digital watches, and digital calculators are some of the most much-using products in our daily life. In the background, to make these gadgets work as per our desire there are many simple components necessary for electronics to function like resistors, capacitors, inductors, etc., these are three basic circuit elements. The Memristor is one such component. This paper provides simulation results of the memristor circuit and its V-I characteristics at different functions as an input signal. A well-trained ANN can able to recognize images with higher precision. To enhance the properties like accuracy, precision, and efficiency in recognition memristor characteristics are introduced to the neural network but previous devices experience some non-linearity issues causing conductance tuning problems. At the same time to be as advanceable in some applications, ANN requires a huge amount of vector-matrix multiplication based on in-depth network expansion. An ionic floating gate (IFG) device with the characteristics of a memristive device can solve these problems. This work proposes a fully connected ANN using the IFG model, the simulation results of the IFG model are given as synapses in deep learning. We use algorithms like the Gradient-descent model, Forward and Backward propagation for network building, and weight setting in neural networks to enhance their ability to recognize images. To be an activation function in the neural network ReLu function is used to avoid vanishing gradients. Here in this paper, we can see how images were recognized by their front view, top view, and side view.

Near-IR (NIR) region of the synchrotron-IR beam, which is usually filtered out in order to improve the signal to noise ratio of Fourier-transform infrared spectroscopy (FTIR), was extracted and used as an illuminating source to achieve phase imaging of biochemical samples. A 200-um pinhole was aligned with one lobe of the unique fork shaped NIR synchrotron beam at a resulting intensity maximum. The diffracted light with airy diffraction pattern passed the biochemical sample and was collected by NIR sensitive lensless camera. The Gerchberg-Saxton algorithm (GSA) was used to reconstruct the phase images of the samples from recorded the intensity images.

The creation of fascinating optical effects such as negative refractive, optical magnetism, and cloaking has become a human dream since the late 1940s, when artificially designed materials, so-called optical metamaterials, were investigated. They are therefore highly interesting for many future applications in many fields. Fabrication of 3D optical metamaterials, which would enable the use of their full potential, remains challenging due to the limitations of conventional manufacturing techniques. An approach that has been proved to be suitable to overcome this challenge is multi-photon lithography (MPL)^[1], which is a true 3D printing technique with high resolution down to sub-100 nm.

In this work, the high potential of using MPL for metamaterial research is further underlined by demonstrating a procedure to process metamaterials operating at low THz frequency (1-10 THz) and generate novel devices as perfect absorbers and electromagnetic waves attenuator. In these frequencies there is no natural element that can interact with electromagnetic fields. Simulation by Finite Differential Time Domain (FDTD) method were done to design the materials’ geometry giving the optimal dimensions and properties for the structure. As a photosensitive material for the MPL an organic – inorganic photopolymer SZ2080™ was used. After MPL processing, the structures were further processed using selective electroless plating to cover the polymer with silver via chemical procedure, so the spectral characterization (absorbance, transmittance, reflectance) can be done at THz frequencies.

[1] Farsari, M., Chichkov, B. Two-photon fabrication. Nature Photon 3, 450–452 (2009), https://doi.org/10.1038/nphoton.2009.131

Incoherent digital holography (IDH) is a technique to obtain a three-dimensional (3D) image of spatially incoherent light diffracted from an object as an incoherent hologram. High-speed image sensing and robustness against external vibrations are important factors when constructing a multidimensional IDH system. Single-shot IDH using single-shot phase-shifting interferometry has been proposed as an IDH technique to satisfy the factors. Full color holographic 3D motion-picture imaging of daily-use light at a frame rate of a color polarization-imaging camera can be achieved by the combination of IDH and single-shot phase-shifting. We show experimental results for color 3D motion-picture imaging in the presentation.

Abstract: The electrocardiogram (ECG) is a biological signal that is frequently employed and plays a significant role in cardiac analysis. In analysis of important indicators of the distribution of ECG record of patient. The R wave is crucial for both analyzing abnormalities in cardiac rhythm and determining heart rate variability (HRV). In this article, a brand-new method for classifying and detecting QRS peaks in ECG data based on artificial intelligence is provided. The integration of the ECG signal data is proposed using a reduced order IIR filter design. To construct the reduced order filter, the filter coefficient is optimized using the min-max method. The main focus of this study is on removing baseline uncertainty and power line interferences from the ECG signal. According to the results, the accuracy has increased by about 13.5% in comparison to the fundamental Pan-Tompkins approach and by about 8.1% in comparison to the current IIR-filter-based categorization rules.

As most of the postgraduate students doing specialization in surgical field ( even orthopedics ) in mid level tertiary care center, peripheral center and post graduation in corporate hospitals where the access to anatomy dissection hall to learn in depth anatomy would be difficult which is required for better understanding of the students while doing surgeries and to learn the techniques real quick, hologram will make way easier for the students to achieve this lag. In Hologram, as we get virtual 3D imaging, it helps students to see the anatomy in par with the cadavers in the dissection hall which would be difficult and costlier to maintain in most of the centers.

Hologram will change the learning technique of the students by providing virtual imaging for better understanding of the subject. Addition of simulations of some basic surgeries will even make the residents learn faster and decrease the chances of making mistakes while doing real time surgeries in future. Holograms can change the way of learning in future and make every surgeon know what they want.

We previously developed an incoherent holography technique for use in lattice light sheet (LLS) microscopes, that represents a specialized adaptation of light sheet microscopy. Light sheet instruments resolve 3D information by illuminating the sample at 90^o to the imaging plane with a sheet of laser light that excites fluorophores in the sample only in a narrow plane. Imaging this plane and then moving it in the imaging z-axis allows construction of the sample volume. Among these types of instruments, LLS microscopy gives higher z-axis resolution and tissue depth penetration. It has a similar working principle to light sheet fluorescence microscopy, but uses a lattice configuration of Bessel beams, instead of Gaussian beams. Our incoherent light detection technique replaces the glass tube lens of the original LLS with a dual diffractive lens system to retrieve the axial depth of the sample. Here, we show that the system is applicable to the light sheet instruments. To make a direct comparison in the same emission light path, we can imitate the nature of non-Bessel light sheet systems by altering the mask annuli used to create Bessel beams in the LLS system. We change the diffractive mask annuli from a higher NA anulus to a smaller NA anulus. This generates a Gaussian excitation beam similar to conventional light sheet systems. Using this approach, we propose an incoherent light detection system for 3D imaging by choosing a variable NA and moving only the light sheet while keeping the sample stage and detection microscope objective stationary.