Photonic crystal microspheres

Zhokhov, A. A.; Масалов, В. М.; Сухинина, Н. С.; Матвеев, Д. В.; Долганов, П. В.; Долганов, В. К.; Емельченко, Г. А.

doi:10.1016/j.optmat.2015.09.019

Cited by 18 publications

(10 citation statements)

References 33 publications

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“…For a pure photonic crystal, we have a twocomponent system consisting of SiO 2 globules and the air. In publications [20,21] it was shown that the pores make up 26% of the total PC volume. Therefore, we take f 1 = 0.74 and f 2 = 0.26.…”

Section: Optical Experimentsmentioning

confidence: 99%

Synthesis and properties of SiO2 photonic crystals modified by DNA

2020

Biophysical Bulletin

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Background: Photonic crystals are structures characterized by periodic modulations of the refractive index with a period commensurate with the wavelength. This periodicity is associated with the existence of a complete band gap in the spectrum of the electromagnetic states of the crystal. The stop zone is called the band gap for the highlighted direction in the crystal. Globular photonic crystals are called three-dimensional photonic crystals, which consist of the same diameter globules. The pores between the globules in the opal allow one to change the refractive index and optical contrast of the material. The task of controlling the stop-zone frequency limits of a globular photonic crystal without changing its physical structure is of practical interest. The easiest way to control the stop-zone parameters is to fill the pores of the photonic crystals with materials with different refractive indices, for example, DNA. Control of the optical parameters of a globular photonic crystal can be used for the creation of optical detectors, sensors, test systems, a quantum biocomputer as well as analyzing and studying a conformational state of DNA. Objectives: the creation of SiO2 globular photonic crystals modified by DNA and studying of the influence of DNA on their optical properties. Materials and Methods: Ethyl alcohol, distilled water, ammonium hydroxide, tetraethoxysilane and DNA were used to synthesize SiO2 photonic crystals. Aqueous DNA solution was used to infiltrate the photonic crystals. We used a visible range spectroscopy for optical experiments and a finite-difference time-domain (FDTD) method for numerical calculations. Results: SiO2 globular photonic crystals modified by DNA were synthesized with 195 nm globules. The reflection spectra of the obtained photonic crystals were measured. A red-shift of the stop-zone maximum after the infiltration of photonic crystals with DNA molecules was found. The electric field distribution was calculated for the photonic crystal with 200 nm globules. Conclusions: FDTD calculations in the linear mode show that the presence of point defects in the structure of the photonic crystal influences the amplification of the local electric field in the interglobular space of the photonic crystal, which houses the DNA molecule at infiltration. The DNA infiltration into the pores of a photonic crystal changes the effective refractive index of the system by 5.99%. Synthesis SiO2 photonic crystals with DNA leads to the formation of a more ordered structure at the macro levels. Thus, DNA serves as a template-like structure for photonic crystals to be assembled on. In this case, the effective refractive index of the system increases by 6.01%.

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Section: Optical Experimentsmentioning

confidence: 99%

Synthesis and properties of SiO2 photonic crystals modified by DNA

2020

Biophysical Bulletin

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“…В соответствии с предложенным критерием был изготовлен тестовый объект, показанный на рис. 1 и состоящий из трех медных проволок диаметром 80 µm, расположенных параллельно друг другу в стеклянной кювете, заполненной водным раствором монодисперсных наночастиц с концентрацией 0.25%, в качестве которых были использованы частицы аморфного кремния диаметром 400 nm, изготовленные методом Штобера [33,34]. Концентрация раствора была выбрана произвольно для демонстрации предлагаемого подхода.…”

Section: тестовый объектunclassified

Экспериментально Обучаемый Метод Фильтрации Шумов Рассеяния В Сигналах Оптической Когерентной Томографии-=sup=-*-=/Sup=-

Долганова¹,

Черномырдин²,

Александрова³

et al. 2019

Журнал Технической Физики

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A method for wavelet filtration procedure training for optical coherence tomography (OCT) images using the experimental measurements of test objects that were constructed by means of water solutions of monodisperse nanoparticles and several microscopic inclusions has been described in the present paper. The choice of test-object parameters (concentration of water solution, size of nanoparticles, and shape, dimensions, and mutual position of inclusions) has allowed the modeling of various working conditions of OCT and setting different criteria for estimation of filtration efficiency. In the present work, the optimal filter for the considered example of a test object has been selected among the combinations of various basic functions of five wavelet families, soft and hard threshold filtering methods, four decomposition levels, and threshold values in a range of 0.05–3.05. The mutual position of the micro-inclusions has been used as a criterion for evaluating the filtration efficiency. As a result, it has been shown that the determined wavelet filter leads to effective suppression of the scattering noise in OCT images and preserve information about the structure of the object under study.

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“…We use nanoparticles with diameter of about 400 nm, synthesized by the multistage Stober method. 54,55 Third, we fill the cuvette with the prepared colloidal suspension. During the described preparation of the test-object, we can precisely control its geometrical parameters and scattering properties.…”

Section: Nanoparticle-based Test-objectmentioning

confidence: 99%

Nanoparticle-enabled experimentally trained wavelet-domain denoising method for optical coherence tomography

et al. 2018

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We present the nanoparticle-enabled experimentally trained wavelet-domain denoising method for optical coherence tomography (OCT). It employs an experimental training algorithm based on imaging of a test-object, made of the colloidal suspension of the monodisperse nanoparticles and contains the microscale inclusions. The geometry and the scattering properties of the test-object are known a priori allowing us to set the criteria for the training algorithm. Using a wide set of the wavelet kernels and the wavelet-domain filtration approaches, the appropriate filter is constructed based on the test-object imaging. We apply the proposed approach and chose an efficient wavelet denoising procedure by considering the combinations of the decomposition basis from five wavelet families with eight types of the filtration threshold. We demonstrate applicability of the wavelet-filtering for the in vitro OCT image of human brain meningioma. The observed results prove high efficiency of the proposed OCT image denoising technique.

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Photonic crystal microspheres

Cited by 18 publications

References 33 publications

Synthesis and properties of SiO2 photonic crystals modified by DNA

Synthesis and properties of SiO2 photonic crystals modified by DNA

Экспериментально Обучаемый Метод Фильтрации Шумов Рассеяния В Сигналах Оптической Когерентной Томографии-=sup=-*-=/Sup=-

Nanoparticle-enabled experimentally trained wavelet-domain denoising method for optical coherence tomography

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