Detailed Treatment of the Nonlinear Optical Properties of Nonlinear Photonic Crystals

Geon Joon Lee,이영백,Hyun-Yong Kim,Sunman Kim,박인규 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.3

Nonlinear photonic crystals were designed such that the center wavelength of the photonic bandgap could be located near 800 nm. The transmission spectrum was obtained by applying the optical transfer matrix formalism to the photonic crystal. The transmission spectrum of the photonic crystal revealed a defect mode resonance and a broad photonic band gap. The spatial optical intensity distribution was obtained by applying the Helmholtz equation to the photonic crystal structure. The intensity distribution exhibited strong confinement of the optical field inside the defect layer. The spatial variation of the electric permittivity was induced by the spatial optical intensity distribution inside the nonlinear defect layer. The nonlinear optical properties of these nonlinear photonic crystals were investigated by applying the finite-difference time-domain method (FDTD) to the photonic crystal structure with a spatially varying electric permittivity. The nonlinear transmission characteristics obtained by using the FDTD method were compared with those obtained by using the spatial average of the spatial optical intensity distribution. The effects of the nonlinear absorption, the nonlinear refraction, and the optical intensity on the nonlinear transmission were investigated.

Photonic Crystals: Integration of Colloidal Photonic Crystals toward Miniaturized Spectrometers (Adv. Mater. 9/2010)

Kim, Shin-Hyun,Park, Hyo Sung,Choi, Jae Hoon,Shim, Jae Won,Yang, Seung-Man WILEY-VCH Verlag 2010 Advanced materials Vol.22 No.9

<B>Graphic Abstract</B> <P>The cover shows a schematic illustration of patterned colloidal photonic crystals with different bandgap positions. When an unknown light source impinges on the patterned photonic crystals, the light information can be identified from the reflection intensity profile of the constituent photonic crystals. The two optical microscopy images and background image display integrated photonic crystals with 20 different bandgaps spanning the entire visible range, and the SEM image shows the cross-section of the photonic crystal stripes, as reported by Shin-Hyun Kim, Seung-Man Yang, and co-workers on p. 946. <img src='wiley_img_2010/09359648-2010-22-9-ADMA201090022-content.gif' alt='wiley_img_2010/09359648-2010-22-9-ADMA201090022-content'> </P>

총설 : 3차원 광밴드갭 결정: 제조와 응용

양승만 ( Seung Man Yang ),이기라 ( Gi Ra Yi ) 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.3

Photonic crystals are referred to as semiconductors for light and can control the flow of photons in microscopic space since semiconductors do the flow of electrons in ULSI(Ulta Large Scale Integration) circuits. Therefore, photonic crystals have attracted enormous attention due to their potential applications including channel-drop filters, nanolasers, optical waveguides and others that are required for the development of next-generation optical telecommucation devices and optical computers. Photonic crystal balls at micrometer scales can be also used as full-color pixel sources in fabrication of three-dimensional photonic crystals have attracted enormous attention due to their potential applications including channel-drop filters, nanolasers, optical waveguides and others that are required for the development of next-generation optical telecommunication devices and optical computers. Photonic crystal balls at micrometer scales can be also used as full-color pixel sources in the pioneering microdissional photonic crystals, and their potential application areas. In particular, we emphasize the colloidal self-assembly scheme that is the most attractive to chemical engineers among several synthetic methods.

Colloidal Optics and Photonics: Photonic Crystals, Plasmonics, and Metamaterials

이재원,이승우 한국광학회 2023 Current Optics and Photonics Vol.7 No.6

The initial motivation in colloid science and engineering was driven by the fact that colloids can serve as excellent models to study atomic and molecular behavior at the mesoscale or microscale. The thermal behaviors of actual atoms and molecules are similar to those of colloids at the mesoscale or microscale, with the primary distinction being the slower dynamics of the latter. While atoms and molecules are challenging to observe directly in situ, colloidal motions can be easily monitored in situ using simple and versatile optical microscopic imaging. This foundational approach in colloid research persisted until the 1980s, and began to be extensively implemented in optics and photonics research in the 1990s. This shift in research direction was brought by an interplay of several factors. In 1987, Yablonovitch and John modernized the concept of photonic crystals (initially conceptualized by Lord Rayleigh in 1887). Around this time, mesoscale dielectric colloids, which were predominantly in a suspended state, began to be self-assembled into three-dimensional (3D) crystals. For photonic crystals operating at optical frequencies (visible to near-infrared), mesoscale crystal units are needed. At that time no manufacturing process could achieve this, except through colloidal self-assembly. This convergence of the thirst for advances in optics and photonics and the interest in the expanding field of colloids led to a significant shift in the research paradigm of colloids. Initially limited to polymers and ceramics, colloidal elements subsequently expanded to include semiconductors, metals, and DNA after the year 2000. As a result, the application of colloids extended beyond dielectric-based photonic crystals to encompass plasmonics, metamaterials, and metasurfaces, shaping the present field of colloidal optics and photonics. In this review we aim to introduce the research trajectory of colloidal optics and photonics over the past three decades; To elucidate the utility of colloids in photonic crystals, plasmonics, and metamaterials; And to present the challenges that must be overcome and potential research prospects for the future.

1P-120 Improved Photonic Property of Quasi-amorphous Photonic Solution by Introducing Imaginary Part of Refractive Index

서춘희,강영종 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

General photonic crystals are made up materials that have different real part of refractive index and until now, imaginary part of refractive index in photonic crystals is not considered. So, we investigated how absorbance affect to reflectance of photonic crystals and use polydopamine (PDA) nanoparticles as absorbing material. When PDA put into SiO₂ quasi-amorphous photonic solution (QAPS), PDA/SiO₂ QAPS shows high contrast photonic color and enhanced reflectance. Also, when dye trapped polystyrene (PS) nanoparticles are added in QAPS, novel phenomena occurred. Only when photonic bandgap region matched with absorbance band of dye, reflectance of QAPS enhanced. Otherwise reflectance intensity not changed. This result show interplay between absorption and reflectance and considerably encourage in field of optics using photonic crystals.

Colloidal Crystallization in Spherical Confining Geometry

김신현 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

Monodisperse colloids spontaneously form crystalline structures that show photonic effect, appealing for various applications. In particular, photonic capsules containing colloidal crystals provide ease of processing and reconfigurability. However, crystals are incompatible with spherical confinement. Minimum energy states of the crystals in spherical volume have yet been intensively explored. Here, we study the crystallization of colloids confined in emulsion drops. With dynamic concentration, face-centered cubic lattice is formed along the curved surface with numerous defects. In the absence of concentration, interparticle potential significantly influences the structure. Weak attractive potential leads to the formation of many small grains with single crystals, whereas strong potential results in random aggregates. On the other hand, weak repulsive potential allows the evolution from the surface crystal to the single crystal, whereas strong potential ends up with surface crystals.

Negative-refraction Effect for Both TE and TM Polarizations in Two-dimensional Annular Photonic Crystals

Hong Wu,Feng Li 한국광학회 2018 Current Optics and Photonics Vol.2 No.1

We systematically investigated the negative-refraction effect for both TE and TM polarizations in annular photonic crystals. Since two polarization waves are excited in different bands, they result in different refractive angles, and so polarization beam splitters can be made of annular photonic crystals. It was found that, in comparison to normal square-lattice air-hole photonic crystals, annular photonic crystals have a much wider common frequency band between TE-1 and TM-2, which is quite beneficial to finding the overlap between the negative-refraction regions belonging to TE-1 and TM-2 respectively. Further analyses of equifrequency surfaces and the electric-field distribution of annular photonic crystals with different parameters have not only demonstrated how the filling factor of annular cells affects the formation of the common negative-refraction region between TE-1 and TM-2, but also revealed some ways to improve the performance of a polarization beam splitter based on the negative-refraction effect in an annular photonic crystal.

Holographic Polymer-Dispersed Liquid Crystals and Polymeric Photonic Crystals Formed by Holographic Photolithography

Kyu Thein,Meng Scott,Duran Hatice,Nanjundiah Kumar,Yandek Gregory R. The Polymer Society of Korea 2006 Macromolecular Research Vol.14 No.2

The present article describes the experimental and theoretical observations on the formation of holographic, polymer-dispersed, liquid crystals and electrically switchable, photonic crystals. A phase diagram of the starting mixture of nematic liquid crystal and photo-reactive triacrylate monomer was established by means of differential scanning calorimetry (DSC) and cloud point measurement. Photolithographic patterns were imprinted on the starting mixture of LC/triacrylate via multi-beam interference. A similar study was extended to a dendrimer/photocurative mixture as well as to a single component system (tetra-acrylate). Theoretical modeling and numerical simulation were carried out based on the combination of Flory-Huggins free energy of mixing and Maier-Saupe free energy of nematic ordering. The combined free energy densities were incorporated into the time-dependent Ginzburg-Landau (Model C) equations coupled with the photopolymerization rate equation to elucidate the spatio-temporal structure growth. The 2-D photonic structures thus simulated were consistent with the experimental observations. Furthermore, 3-D simulation was performed to guide the fabrication of assorted photonic crystals under various beam-geometries. Electro-optical performance such as diffraction efficiency was evaluated during the pattern photopolymerization process and also as a function of driving voltage.

Calculation of the Berry curvature and Chern number of topological photonic crystals

Goudarzi Kiyanoush,Maragheh Hatef Ghannadi,Lee Moonjoo 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.81 No.5

In this paper, numerical calculations of the Berry curvature and Chern number of two types of two-dimensional photonic crystals consisting isotropic dielectric and anisotropic magneto-optical, gyromagnetic, rods in air in a square lattice are studied. The Chern number, an integer number, is a key parameter to distinguish between trivial and non-trivial photonic crystals. Trivial and non-trivial photonic crystals reveal zero and non-zero Chern numbers. A non-zero Chern number is achieved through the breaking of time-reversal and inversion symmetries. The results for two-dimensional photonic crystals containing isotropic dielectric and gyromagnetic materials under TM mode illustrate zero and 0, 1, -2, and -1 Chern numbers for the frst four bands, respectively. The creation of non-zero Chern numbers brings a new way of designing one-way, robust to arbitrary disorder, and zero back-refection photonic components

Photonic Crystals: Photoresponsive Block Copolymer Photonic Gels with Widely Tunable Photosensitivity by Counter‐Ions (Adv. Mater. 23/2012)

Ahn, Youshin,Kim, Eunjoo,Hyon, Jinho,Kang, Changjoon,Kang, Youngjong WILEY‐VCH Verlag 2012 Advanced Materials Vol.24 No.23

<P>Block copolymer photonic gels exhibiting multiple colors in response to near‐UV radiation are demonstrated by Y. Kang and co‐workers on page OP 127. The counterions pairing with the polyelectrolyte in the gel layers determine the photosensitivity of photonic gels. The simple replacement of ions can make the photonic gels either highly sensitive or insensitive to near‐UV. The illustration shows ionic signaling giving “STOP” and “GO” cues for the photoresponse of these photonic gels. </P>