Thank you for reading principles of optics electromagnetic theory of propagation interference and diffraction of light. As you may know, people have search hundreds times for their favorite novels like this principles of optics electromagnetic theory of propagation interference and diffraction of light, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some infectious bugs inside their computer.

Principles Of Optics Electromagnetic Theory Of Propagation Interference And Diffraction Of Light

The proliferation and transmission of viruses has become a threat to worldwide biosecurity, as exemplified by the current COVID-19 pandemic. Early diagnosis of viral infection and disease control have always been critical. Virus detection can be achieved based on various plasmonic phenomena, including propagating surface plasmon resonance (SPR), localized SPR, surface-enhanced Raman scattering, surface-enhanced fluorescence and surface-enhanced infrared absorption spectroscopy. The present review covers all available information on plasmonic-based virus detection, and collected data on these sensors based on several parameters. These data will assist the audience in advancing research and development of a new generation of versatile virus biosensors.

/pdf/a-comprehensive-review-on-plasmonic-based-biosensors-used-in-4l57kaft9n.pdf

A comprehensive review on plasmonic-based biosensors used in viral diagnostics.

Optical spectrometry is a tool to investigate wavelength-dependent light–matter interactions and is widely used in astronomy, physics and chemistry. Integration and miniaturization of the currently bulky spectrometers will have an impact on applications where compactness and low complexity are key, such as air- and spaceborne missions. A high-resolution spectroscopy principle based on the near-field detection of a spatial standing wave inside a subwavelength waveguide has shown great promise to accomplish some of the aforementioned demands. However, small-scale devices based on this principle face strong bandwidth limitations due to undersampling of the standing wave. Here, we demonstrate an integrated single-waveguide Fourier transform spectrometer with an operational bandwidth of 500 nm in the near- and short-wavelength infrared, not relying on any moving components. The prototype device, with a footprint of less than 10 mm2, exploits the electro-optic properties of thin-film lithium niobate in order to retrieve the complete spatial interferogram. By exploiting the electro-optic properties of thin-film lithium niobate, an integrated single-waveguide Fourier transform spectrometer with a footprint of <10 mm2 and an operational bandwidth of 500 nm in the near- and short-wavelength infrared is demonstrated.

An integrated broadband spectrometer on thin-film lithium niobate

To study the effect of the lateral substituents on the UV stability of high birefringence liquid crystals (LCs), computational chemistry was used to examine a series of high birefringence LCs based on a diphenyl-diacetylene (DPDA) central core, thiophene segments as elongated π-conjugated units and four electron-withdrawing groups (-F, -CF3, -OCF3, -CN) as lateral substituents. In the present study, geometry optimisations have been performed using the DFT/B3LYP/6-311G (d, p) method. Out of a series of functional and basis sets examined, the functional ωB97X-D and basis set 6-31G (d, p) are most successful in predicting charge transfer absorption. The theoretical study indicates that the enhancement of UV stability is related with the types, numbers and positions of the lateral substituents. The calculated results indicate that the electron-withdrawing groups can shorten triple bond length, decrease energy gap value and increase the absorption maxima of the high-Δn LCs, which is beneficial for good...

Lateral substituent effects on UV stability of high-birefringence liquid crystals with the diaryl-diacetylene core: DFT/TD-DFT study

Plenoptic cameras generally employ a microlens array positioned between the main lens and the image sensor to capture the three-dimensional target radiation in the visible range. Because the focal length of common refractive or diffractive microlenses is fixed, the depth of field (DOF) is limited so as to restrict their imaging capability. In this paper, we propose a new plenoptic camera using a liquid crystal microlens array (LCMLA) with electrically tunable focal length. The developed LCMLA is fabricated by traditional photolithography and standard microelectronic techniques, and then, its focusing performance is experimentally presented. The fabricated LCMLA is directly integrated with an image sensor to construct a prototyped LCMLA-based plenoptic camera for acquiring raw radiation of targets. Our experiments demonstrate that the focused region of the LCMLA-based plenoptic camera can be shifted efficiently through electrically tuning the LCMLA used, which is equivalent to the extension of the DOF.

An electrically tunable plenoptic camera using a liquid crystal microlens array

Spectroscopic imaging has been proved to be an effective tool for many applications in a variety of fields, such as biology, medicine, agriculture, remote sensing and industrial process inspection. However, due to the demand for high spectral and spatial resolution it became extremely challenging to design and implement such systems in a miniaturized and cost effective manner. Using a Compressive Sensing (CS) setup based on a single variable Liquid Crystal (LC) retarder and a sensor array, we present an innovative Miniature Ultra-Spectral Imaging (MUSI) system. The LC retarder acts as a compact wide band spectral modulator. Within the framework of CS, a sequence of spectrally modulated images is used to recover ultra-spectral image cubes. Using the presented compressive MUSI system, we demonstrate the reconstruction of gigapixel spatio-spectral image cubes from spectral scanning shots numbering an order of magnitude less than would be required using conventional systems.

Miniature Compressive Ultra-spectral Imaging System Utilizing a Single Liquid Crystal Phase Retarder

Multispectral tunable filters with high performance are desirable components in various biomedical and industrial applications. In this Letter, we present a new narrowband multispectral tunable filter with high throughput over a wide dynamic range. It is composed from a wideband large dynamic range liquid crystal tunable filter combined with a multiple narrowbands spectral filter made of two stacks of photonic crystals and cavity layer in between. The filter tunes between nine spectral bands covering the range 450–1000 nm with bandwidth 80%.

Narrowband multispectral liquid crystal tunable filter.

The wavelength dependence of phase retarders is considered as a challenge in different applications such as polarimetric systems. A novel achromatic waveplate based on two nematic liquid crystal retarders is designed and demonstrated tunable over a wide spectral range using different voltages applied to the two retarders. The achromatic behavior is achieved based on the fact that the dispersion of the retardation of liquid crystals is voltage dependent. Achromatic quarter and half-waveplates are demonstrated using the same device as well as the tunability of the achromatic operation range.

Tunable achromatic liquid crystal waveplates

A new technique for birefringence measurement and extracting the coefficients of the dispersion relation such as Cauchy or Sellmeier equations is proposed. The main principle of the technique is based on finding accurately the wavelengths that the birefringent plate operates as a quarter-wave plate (QWP) and measuring the birefringence at these points. As the projections of the ordinary and extraordinary beams on the analyzer axis interfere, the setup is a form of common path interferometer and these QWP points are the quadrature points at which the sensitivity of the interferometer is optimum. An algorithm is developed to find these crossing points precisely. Implementation of this technique has been done on two different kinds of nematic liquid crystal wave plates made of Merck E44 and BL036.

Birefringence measurement using rotating analyzer approach and quadrature cross points

In this paper, we present a new hyperspectral compact camera which is designed to have high spatial and spectral resolutions, to be vibrations tolerant, and to achieve state-of-the-art high optical throughput values compared to existing nanosatellite hyperspectral imaging payloads with space heritage. These properties make it perfect for airborne and spaceborne remote sensing tasks. The camera has both hyperspectral and panchromatic imaging capabilities, achieved by employing a wedge-shaped liquid crystal cell together with computational image processing. The hyperspectral images are acquired through passive along-track spatial scanning when no voltage is applied to the cell, and the panchromatic images are quickly acquired in a single snapshot at a high signal-to-noise ratio when the cell is voltage driven.

/pdf/dual-camera-design-for-hyperspectral-and-panchromatic-o8nqtg7dk1.pdf

Marwan J. Abuleil

Papers

Miniature Compressive Ultra-spectral Imaging System Utilizing a Single Liquid Crystal Phase Retarder

Narrowband multispectral liquid crystal tunable filter.

Tunable achromatic liquid crystal waveplates

Birefringence measurement using rotating analyzer approach and quadrature cross points

Dual-camera design for hyperspectral and panchromatic imaging, using a wedge shaped liquid crystal as a spectral multiplexer