The structural modification of Ba<sub>0.5</sub>Sr<sub>0.5</sub>TiO<sub>3</sub> (BST) nanocatalyst was successfully synthesized via sol-gel process. The BST catalyst was modified by A-site (A-BST), A-B-site (A-B-BST), and B-site (B-BST) in order to investigate the effect of structurally modified BST catalyst for photocatalytic decolorization of methylene blue. The structurally modified BST catalysts can increase the nonradiation energy such as phonon energy compared to that of BST one. The partial incorporation of the A-BST catalyst was evidenced by the higher-ordered structure by increasing number of Ti<sup>4+</sup> ions and the lattice oxygen. The A-B-BST and A-BST catalysts were given more electron-transfer in the TiO<sub>6</sub> than that of BST and B-BST catalysts, respectively. The A-B-BST catalyst promoted the oxidation of the lattice oxygen by holes capturing to form the chemisorbed oxygen, presenting the highest photobleaching activity of methylene blue. On the other hand, more oxygen vacancies recombination of BST catalyst compared to that of structurally modified BST catalysts presented the reduction of photocatalytic activity.

Tassanee Tubchareon

Rachan Klaysri

Piyasan Praserthdam

A Comparison of Different A-, A-B-, and B-Site Incorporated in (Ba<sub>0.5</sub>Sr<sub>0.5</sub>)TiO<sub>3</sub> on Photocatalytic Application

A new organic charge transfer molecular complex salt of benzimidazolium salicylate (BSL) single crystals was grown by the slow evaporation solution growth technique using methanol as a solvent at room temperature. The grown crystals were characterised by single crystal X-ray diffraction (XRD) which confirms that the crystal belongs to monoclinic system with the centrosymmetric space group P2<sub>1</sub>/<svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.2063904pt" id="M1" height="6.1673pt" version="1.1" viewBox="-0.0498162 -5.96091 5.39742 6.1673" width="5.39742pt"><g transform="matrix(.013,0,0,-0.013,0,0)"><path id="g113-100" d="M383 397C383 424 344 448 299 448C244 448 172 409 132 375C66 319 23 227 23 146C23 42 74 -12 146 -12C208 -12 298 30 359 103L343 124C315 95 248 48 192 48C145 48 111 85 111 163C111 228 129 294 151 330C171 363 201 401 241 401C275 401 302 384 325 356C332 347 339 344 348 348C373 360 383 381 383 397Z"/><glyph.data ascent="3473" descent="-2876" horiz-adv-x="406" vert-adv-y="406"/></g></svg>. The crystalline perfection of the grown crystal was analyzed by high resolution X-ray diffraction (HRXRD). The presence of various functional groups was identified by FTIR spectrum. UV-Vis spectral study reveals that the BSL crystal is optically transparent in the wavelength region 342 nm–1100 nm. Dielectric measurements of the crystal at various frequencies were also determined. The mechanical properties of the grown crystal were assessed using Vickers microhardness testing. Nonlinear optical property of the crystal was confirmed using Kurtz and Perry powder technique and the SHG efficiency of the BSL crystal is 0.7 times greater than that of the standard KDP crystal.

M. Amudha

R. Rajkumar

V. Thayanithi

P. Praveen Kumar

Growth and Characterization of Benzimidazolium Salicylate: NLO Property from a Centrosymmetric Crystal

We propose a uniform solution for a future client-side 400&#x2009;G Ethernet standard based on MultiCAP advanced modulation format, intensity modulation, and direct detection. It employs 4 local area networks-wavelength division multiplexing (LAN-WDM) lanes in 1300&#x2009;nm wavelength band and parallel optics links based on vertical cavity surface emitting lasers (VCSELs) in 850&#x2009;nm wavelength band. Total bit rate of 432&#x2009;Gbps is transmitted over unamplified 20&#x2009;km standard single mode fiber link and over 40&#x2009;km link with semiconductor optical amplifier. 70.4&#x2009;Gb/s transmission over 100&#x2009;m of OM3 multimode fiber using off-the-shelf 850&#x2009;nm VCSEL with 10.1&#x2009;GHz 3&#x2009;dB bandwidth is demonstrated indicating the feasibility of achieving 100&#x2009;Gb/s per lane with a single 25&#x2009;GHz VCSEL. In this review paper we introduce and present in one place the benefits of MultiCAP as versatile scheme for use in a number of client-side scenarios: short range, long range, and extended range.

Anna Tatarczak

Miguel Iglesias Olmedo

Tianjian Zuo

Jose Estaran

Jesper Bevensee Jensen

Xiaogeng Xu

Idelfonso Tafur Monroy

Enabling 4-Lane Based 400&#x2009;G Client-Side Transmission Links with MultiCAP Modulation

We propose an optical spatial filter (OSF) method to suppress beam wander and spatial noise effects. Signal from random displacements of the focus spot around the optical axis within the constricted area is collected. This method advantageously suppresses fluctuations in signal intensity. The OSF consists of a pinhole and cone reflector. The pinhole produces Fresnel diffraction on the focus spot. The cone reflector provides directed reflectance onto the pinhole for random focus spot displacements due to beam wander. The calculations of signal power are based on fluctuations of signal intensity that are minimized by the circular aperture function of the pinhole and the cosine of the reflectance angle from the cone reflector. The method is applied to free-space optical communications at a wavelength of 1.55&#x2009;<i>&#x3BC;</i>m with an atmospheric chamber to provide optical propagation media. Based on calculations, the beam wander angles that can be received by the OSF are from 14.0&#xb0; to 28.0&#xb0;. Moreover, based on experiment, the OSF with a pinhole diameter of 20.0&#x2009;<i>&#x3BC;</i>m and cone reflector diameter of 1.5&#x2009;mm produces signal power of &#x2212;15.3&#x2009;dBm. Both calculations and experiment show that the OSF enhances the received signal power in the presence of turbulence.

Ucuk Darusalam

Purnomo Sidi Priambodo

Eko Tjipto Rahardjo

Optical Spatial Filter to Suppress Beam Wander and Spatial Noise Induced by Atmospheric Turbulence in Free-Space Optical Communications

We propose a robust method to distinguish isolated single gold nanoparticles (AuNP monomers) and their dimers under Brownian motion, a key for ultrasensitive homogeneous bioassays, including AuNP sandwich assays. To detect dimers and distinguish them from a larger number of monomers in aqueous solution, single-particle polarization microscopy was performed. For the accurate detection of individual particles, the optical anisotropy and rotational diffusion time are measured because a dimer is much more anisotropic than the nearly spherical monomer and the rotational diffusion time of a dimer is four times that of a monomer. By employing an autocorrelation analysis, we defined a measure of distinguishing that simultaneously enables high detection probability and low error probability. The detection platform offers homogeneous DNA hybridization assays and immunoassays at the subpicomolar level.

Jun Kobayashi

Yukari Takeshita

Naoto Mizuno

Keio Esashika

Toshiharu Saiki

Robust Discrimination between Single Gold Nanoparticles and Their Dimers in Aqueous Solution for Ultrasensitive Homogeneous Bioassays

Takashi Yatsui

Chennupati Jagadish

Gilles Lerondel

Nanophotonics: Fabrications and Application of Nanoscale Optics to Novel Photonic Devices

We investigate the modulation of the localized surface plasmon resonance (LSPR) of a gold nanorod (AuNR) using a GeSbTe film as an active medium. We demonstrate high-contrast switching of LSPR in an AuNR/GST/Au thin film sandwich structure upon phase change. To go beyond this single-particle switching functionality, we consider a plasmon particle system interacting with a phase-change material (PCM) to discuss the possibility of parallel processing devices with memory functionality, exploiting the plasticity and threshold behavior that are inherent characteristics of PCMs. We demonstrate that the temporal and spatial evolution of a plasmon-PCM array system can be equivalent to a cellular automata algorithm.

Takashi Hira

Takayuki Uchiyama

Kenta Kuwamura

Yuya Kihara

Tasuku Yawatari

Switching the Localized Surface Plasmon Resonance of Single Gold Nanorods with a Phase-Change Material and the Implementation of a Cellular Automata Algorithm Using a Plasmon Particle Array

By using a homojunction-structured GaP single crystal, we generated a photon energy higher than the bandgap energy (2.26&#x2009;eV). The device was fabricated by performing dressed-photon-phonon- (DPP-) assisted annealing, while applying a forward-bias current, on a p-n homojunction structure formed by implanting a dopant (Zn) into an n-type GaP substrate. The DPP-assisted annealing increased the light emission intensity in an energy band above 2.32&#x2009;eV by at least 550&#x25; compared with that before annealing.

Jun Hyoung Kim

Tadashi Kawazoe

Motoichi Ohtsu

GaP Homojunction LEDs Fabricated by Dressed-Photon-Phonon-Assisted Annealing

We compared dressed-photon-phonon (DPP) etching to conventional photochemical etching and, using a numerical analysis of topographic images of the resultant etched polymethyl methacrylate (PMMA) substrate, we determined that the DPP etching resulted in the selective etching of smaller scale structures in comparison with the conventional photochemical etching. We investigated the wavelength dependence of the PMMA substrate etching using an O<sub>2</sub> gas. As the dissociation energy of O<sub>2</sub> is 5.12&#x2009;eV, we applied a continuous-wave (CW) He-Cd laser (<svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.2129898pt" id="M1" height="9.89089pt" version="1.1" viewBox="-0.0498162 -9.6779 42.7414 9.89089" width="42.7414pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><path id="g113-233" d="M529 97L508 118C475 75 449 58 438 58C428 58 421 66 415 104C393 234 374 403 364 496C345 670 307 712 254 712C220 712 174 691 153 669L161 645C176 653 194 658 206 658C237 658 261 640 278 562C287 522 290 483 293 434C223 269 110 105 23 9L32 -12C59 -6 85 0 108 7C152 64 251 252 300 366C307 297 315 221 337 82C346 24 363 -12 393 -12C425 -12 475 13 529 97Z"/></g><g transform="matrix(.0135,0,0,-0.0135,11.261,0)"><path id="g117-34" d="M535 323V373H52V323H535ZM535 138V188H52V138H535Z"/></g><g transform="matrix(.0135,0,0,-0.0135,22.999,0)"><path id="g113-52" d="M285 378C315 398 338 416 353 432C373 451 384 474 384 503C384 579 325 635 236 635H235C182 635 136 610 108 579L65 516L85 496C110 533 150 575 205 575C258 575 300 543 300 481C300 407 232 369 141 339L147 310C163 315 188 321 211 321C268 321 338 284 338 192C338 94 288 40 217 40C160 40 119 68 93 91C85 98 77 97 69 91C60 84 47 71 46 58C44 46 48 35 62 22C75 10 116 -12 162 -12C234 -12 424 62 424 224C424 297 373 359 285 376V378Z"/></g><g transform="matrix(.0135,0,0,-0.0135,29.502,0)"><path id="g113-51" d="M412 140C382 77 369 73 315 73H129L270 222C362 320 402 379 402 466C402 571 322 635 234 635C177 635 130 609 99 576L42 495L64 475C90 514 133 568 201 568C274 568 318 519 318 435C318 349 255 267 193 193C144 135 87 78 32 23V0H405C417 45 427 89 440 131L412 140Z"/></g><g transform="matrix(.0135,0,0,-0.0135,36.006,0)"><path id="g113-54" d="M153 550H386L412 615L406 623H120L82 318C104 327 142 338 184 338C294 338 347 275 347 187C347 112 305 39 221 39C160 39 119 71 97 89C88 97 80 96 71 90C59 80 50 67 49 57C48 45 52 36 66 23C80 9 123 -12 169 -12C221 -11 288 15 342 59C403 109 431 165 431 225C431 308 366 395 238 395C212 395 165 379 127 364L153 550Z"/></g></svg>&#x2009;nm, 3.81&#x2009;eV) for the DPP etching and a 5th-harmonic Nd:YAG laser (<svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.2129898pt" id="M2" height="9.89089pt" version="1.1" viewBox="-0.0498162 -9.6779 42.7414 9.89089" width="42.7414pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><use xlink:href="#g113-233"/></g><g transform="matrix(.0135,0,0,-0.0135,11.261,0)"><use xlink:href="#g117-34"/></g><g transform="matrix(.0135,0,0,-0.0135,22.999,0)"><use xlink:href="#g113-51"/></g><g transform="matrix(.0135,0,0,-0.0135,29.502,0)"><path id="g113-50" d="M384 0V27C293 34 287 42 287 114V635C232 613 172 594 109 583V559L157 557C201 555 205 550 205 499V114C205 42 199 34 109 27V0H384Z"/></g><g transform="matrix(.0135,0,0,-0.0135,36.005,0)"><use xlink:href="#g113-52"/></g></svg>&#x2009;nm, 5.82&#x2009;eV) for the conventional photochemical etching. From the obtained atomic force microscope images, we confirmed a reduction in surface roughness, <svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-3.427751pt" id="M3" height="12.4257pt" version="1.1" viewBox="-0.0498162 -8.99795 13.9492 12.4257" width="13.9492pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><path id="g113-83" d="M610 18C585 26 567 34 540 68C517 97 499 128 476 171C452 215 425 276 413 304C496 332 570 394 570 494C570 555 545 595 509 619S419 650 364 650H139L133 622C216 615 219 612 203 527L129 132C112 40 105 36 23 28L17 0H279L285 28C199 34 194 40 211 132L239 284H284C320 284 334 275 351 236C374 182 394 140 420 93C459 23 495 -1 592 -8H600L610 18ZM480 485C480 424 449 372 403 342C374 323 338 316 293 316H245L291 562C296 589 301 601 311 608S337 618 358 618C432 618 480 575 480 485Z"/></g><g transform="matrix(.0095,0,0,-0.0095,8.427,3.264)"><path id="g50-98" d="M490 97L476 124C442 96 405 70 398 70C392 70 390 78 396 114C419 243 448 379 463 432L457 436C446 436 431 439 418 442C393 447 368 451 343 451C281 451 204 418 155 381C74 320 24 206 24 107C24 23 59 -12 88 -12C118 -12 155 5 191 34C236 70 290 122 328 177H330L312 84C296 0 311 -12 331 -12C355 -12 425 24 490 97ZM374 387C371 367 360 299 347 264C323 202 187 53 142 53C128 53 113 73 113 120C113 224 157 332 221 380C241 395 274 403 303 403C330 403 360 395 374 387Z"/></g></svg>, in both cases. However, based on calculations involving the standard deviation of the height difference function, we confirmed that the conventional photochemical etching method etched the larger scale structures only, while the DPP etching process selectively etched the smaller scale features.

Wataru Nomura

Realization of Ultraflat Plastic Film Using Dressed-Photon-Phonon-Assisted Selective Etching of Nanoscale Structures

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Advances in Optical Technologies