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>

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.

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.

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.

UV-Nanoimprinted Photonic-Crystal Structure for Organic Light-Emitting Diodes

심종엽(Jongyoup Shim),전소희(Sohee Jeon),윤재륜(Jae-Ryoun Youn),강재욱(Jaewook Kang),김장주(Jang-Joo Kim),김세헌(Se-Heon Kim),정준호(Jun-ho Jeong),최대근(Dae-Geun Choi),김기돈(Ki-Don Kim),알리알툰(Ali Ozhan Altun),최준혁(Junhyuk Choi) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.10

A conventional OLED has only about 20 % light extraction efficiency. When a photonic crystal layer is put in between the anodic layer and the substrate, the light can be extracted to the air by the optical diffraction phenomena. In this article we form a photonic crystal layer (nano-patterned array) directly on the transparent substrate by the UV-nanoimprinting method with a polymer resin. By the FDTD simulation the enhancement of the light extraction is assessed. And the fabrication process details including UV-nanoimprint, SixNy interlayer and OLED layers are presented in this article. The experiment shows that with the imprinted photonic crystal structure the light extraction efficiency is increased by ~50% comparing with the conventional OLED and therefore this nanoimprinted photonic crystal OLED is a promising technology for the future OLED display and illuminator applications.

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.

Ultrahuge Light Intensity in the Gap Region of a Bowtie Nanoantenna Coupled to a Low-mode-volume Photonic-crystal Nanocavity

Nassibeh Ebadi,Reza Yadipour,Hamed Baghban 한국광학회 2018 Current Optics and Photonics Vol.2 No.1

This paper presents a new, efficient hybrid photonic-plasmonic structure. The proposed structure efficiently and with very high accuracy combines the resonant mode of a low-mode-volume photonic-crystal nanocavity with a bowtie nanoantenna’s plasmonic resonance. The resulting enormous enhancement of light intensity of about 1.1 × 10<SUP>7</SUP> in the gap region of the bowtie nanoantenna, due to the effective optical-resonance combination, is realized by subtle optimization of the nanocavity’s optical characteristics. This coupled structure holds great promise for many applications relying on strong confinement and enhancement of optical field in nanoscale volumes, including antennas (communication and information), optical trapping and manipulation, sensors, data storage, nonlinear optics, and lasers.

열처리와 반복코팅이 자기조립을 통해 형성된 SiO₂ 광자결정의 광특성에 미치는 영향

오용택,신동찬 조선대학교 생산기술연구소 2005 生産技術硏究 Vol.27 No.2

This study examined the effect of heat treatment and multi-coating on the microstructure and optical properties of photonic crystals that had been self assembled using monodispersed spherical SiO₂ nanoparticles. When the heat treatment temperature was increased, the reflectance peak due to the photonic band gap moved to a shorter wavelength direction, and the peak intensity of the Fabry Perot fringes increased. The highest reflectance peak intensity was obtained in the sample heat treated at 250~300℃. Heat treatment reduced the average particle size and number of defects, and increased the packing density of the photonic crystal. When the heat treatment temperatures were increased to 900℃, a large crack, whose average size is approximately 1.3 ㎛, formed through the self assembled layer. In addition, a multi-coating could effectively fill the open space of this crack and reduce the total number of defects dramatically.

포토닉 크리스탈 응용을 위한 비정질 칼코게나이드 As-Ge-Se-S 박막의 특성 연구

남기현,구용운,최혁,정홍배,Nam, Ki-Hyun,Ju, Long-Yun,Choi, Hyuk,Chung, Hong-Bay 한국전기전자재료학회 2008 전기전자재료학회논문지 Vol.21 No.6

In this paper, we investigated the properties of chalcogenide glass thin films formed by photo-inducing for use in 1-dimensional photonic crystals. We used Ag-doped amorphous As-Ge-Se-S thin films which belongs in the chalcogenide materials having sensitive photoluminescence properties. The purpose of this experiment is to form the holographic lattice for 1-dimensional photonic crystals. The way in which photo-induce into the amorphous chalcogenide thin films is holographic lithography method. We confirmed the formation of diffraction lattice by sensing the existence of diffraction beam and measured the diffraction efficiency. The results suggest that there is an application possibility with photonic crystals.

Growth and characterization of neodymium and ytterbium doped barium chloride dihydrate single crystals

Kalidasan M.,Baskar K.,Dhanasekaran R. 한국물리학회 2016 Current Applied Physics Vol.16 No.9

Pure, Nd doped and Nd:Yb co-doped barium chloride dihydrate (BaCl2$2H2O) single crystals were grown and analyzed with various characterization techniques. The measured unit cell parameters show that the grown crystals belong to monoclinic system. Powder X-ray diffraction spectra indicates that the dopants enhance (2 1 0) orientation of BaCl2$2H2O crystal. X-ray rocking curves have been recorded to analyze the crystallinity of the grown single crystals. Optical absorption spectra of the grown crystals contain strong absorption bands in infrared region. Spectral overlap of absorption bands of Yb3þ and Nd3þ ion around 850 nme1060 nm in Nd:Yb co-doped single crystal indicates the prospect of energy transfer between them. A significant enhancement has been observed in the photoluminescence spectrum of Nd:Yb codoped single crystal recorded with 244 nm laser excitation. Photon upconversion ability of the crystals was tested using Nd:YAG laser of wavelength 1064 nm. An unusual upconverted green emission from pure centrosymmetric BaCl2$2H2O single crystal has been observed. The energy of upconverted green light of Nd:Yb co-doped barium chloride dihydrate single crystal is higher which may be due to energy transfer occurred between Yb3þ and Nd3þ ions. FTIR and FT-Raman spectral analyses were carried out to study the vibrational modes of pure, Nd doped and Nd:Yb co-doped BaCl2$2H2O single crystals.