In many military and industrial applications, GaAs photovoltaic (PV) converters are connected in series in order to generate the required voltage compatible with most common electronics. Multimode optical fibers are usually used to carry high-intensity laser and illuminate the series connected GaAs PV converters in real time. However, multimode optical fiber illumination has a speckled intensity pattern. The series connected PV array is extremely sensitive to nonuniform illumination; its performance is limited severely by the converter that is illuminated the least. This paper quantifies the effects of multimode optical fiber illumination on the performance of series connected GaAs PV converters, analyzes the loss mechanisms due to speckles, and discusses the maximum illumination efficiency. In order to describe the illumination dependent behavior detailedly, modeling of the series connected PV array is accomplished based on the equivalent circuit for PV cells. Finally, a series of experiments are carried out to demonstrate the theory analysis.

Tiqiang Shan

Xinglin Qi

Performance of Series Connected GaAs Photovoltaic Converters under Multimode Optical Fiber Illumination

SrTiO3:Pr3+ is the most representative titanate matrix red phosphor for field emission display (FED). The red luminous efficiency of SrTiO3:Pr3+ will be greatly improved after the compensation ions codoping, so SrTiO3:Pr3+ red phosphor has been a research focus at home and abroad. SrTiO3:Pr3+, SrTiO3:Pr3+, Mg2+, and SrTiO3:Pr3+, Al3+ phosphors are synthesized by a new sol-gel method. Crystal structure, spectral characteristics, and luminescence enhancement mechanism of the sample were studied by XRD and PL spectra. The results showed that after co-doped, SrTiO3:Pr3+ phosphor is single SrTiO3 cubic phase, the main emission front is located at 614&#x2009;nm, corresponding to Pr3+ ions 1D2<svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.04981995pt" id="M1" height="6.53195pt" version="1.1" viewBox="-0.0498162 -6.48213 17.6151 6.53195" width="17.6151pt"><g transform="matrix(.0135,0,0,-0.0135,2.271,0)"><path id="g117-148" d="M901 255C861 290 790 361 716 442L694 427L796 280H69V230H796L694 83L716 68C790 149 861 220 901 255Z"/></g></svg>3H4 transition emission. SrTiO3:Pr3+, Mg2+ and SrTiO3:Pr3+, Al3+ phosphor luminescence intensity is enhanced, but the main luminescence mechanism is not changed. Acceptor impurity <svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.2129903pt" id="M2" height="6.42315pt" version="1.1" viewBox="-0.0498162 -6.21016 7.70145 6.42315" width="7.70145pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><path id="g113-121" d="M536 404C536 423 520 448 491 448C445 448 398 404 308 283L286 338C255 416 242 448 217 448C182 448 138 402 92 341L111 321C149 368 169 378 178 378C188 378 198 363 214 320L254 212C185 117 138 65 107 65C98 65 85 69 82 75C79 82 73 86 65 86C44 86 23 60 23 39C23 7 44 -12 71 -12C119 -12 168 33 265 177L306 61C321 17 347 -12 373 -12C413 -12 465 33 507 96L491 119C459 84 432 60 413 60C395 60 378 92 358 148L321 250C341 279 369 310 389 332C417 363 439 382 456 382C466 382 475 376 481 368C486 361 492 358 496 358C513 358 536 381 536 404Z"/></g></svg> = Mg2+, Al3+ will replace Ti bit after being doped into the crystal lattice to form <svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-3.313601pt" id="M3" height="14.5635pt" version="1.1" viewBox="-0.0498162 -11.2499 24.0781 14.5635" width="24.0781pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><path id="g190-89" d="M655 0V28C585 35 563 50 517 120C469 193 414 280 360 366C427 469 460 516 481 545C526 604 545 614 619 622V650H391V622C457 614 462 604 438 560C411 511 381 463 339 398C295 466 258 523 225 580C210 606 211 615 272 622V650H26V622C98 614 111 603 154 538C189 482 235 408 288 324C200 188 149 116 124 85C95 47 64 34 7 28V0H236V28C169 36 164 46 188 89C220 148 261 217 310 291C372 193 417 118 442 77C461 44 454 35 392 28V0H655Z"/></g><g transform="matrix(.0095,0,0,-0.0095,8.894,3.264)"><path id="g190-85" d="M592 498C586 556 582 629 581 675H560C545 656 537 650 510 650H115C87 650 74 652 60 675H40C38 620 33 555 28 495H57C69 539 77 568 89 585C102 607 122 616 205 616H267V123C267 44 259 34 168 28V0H454V28C360 34 352 44 352 123V616H422C498 616 514 608 531 584C542 568 552 543 562 495L592 498Z"/></g><g transform="matrix(.0095,0,0,-0.0095,14.593,3.264)"><path id="g190-106" d="M135 536C164 536 186 560 186 587C186 617 164 639 136 639C109 639 85 617 85 587C85 560 109 536 135 536ZM252 0V26C188 32 181 38 181 106V451C138 433 90 420 39 412V388C99 379 102 374 102 312V106C102 38 95 32 32 26V0H252Z"/></g><g transform="matrix(.0095,0,0,-0.0095,17.664,-5.984)"><path id="g54-33" d="M556 236V289H56V236H556Z"/></g></svg> charge compensation corresponding defect centers <svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-3.4468pt" id="M4" height="14.6967pt" version="1.1" viewBox="-0.0498162 -11.2499 27.4778 14.6967" width="27.4778pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><path id="g190-81" d="M46 650V622C120 617 128 613 128 525V125C128 42 120 34 40 28V0H311V28C221 34 212 39 212 124V281L286 262C297 261 316 261 331 263C429 275 526 338 526 468C526 533 501 579 462 609C422 638 364 650 293 650H46ZM212 559C212 588 215 600 223 606C230 613 251 618 279 618C361 618 430 572 430 464C430 337 350 302 285 302C252 302 225 309 212 314V559Z"/></g><g transform="matrix(.0135,0,0,-0.0135,7.505,0)"><path id="g190-115" d="M181 342V451C133 431 89 419 40 411V388C98 381 102 377 102 311V104C102 38 95 32 33 26V0H263V26C186 32 181 38 181 104V287C203 343 235 372 261 372C277 372 289 366 304 352C310 346 318 345 330 350C349 359 362 379 362 399C362 422 338 449 304 449C256 449 213 393 183 342H181Z"/></g><g transform="matrix(.0095,0,0,-0.0095,12.579,3.264)"><path id="g190-84" d="M409 504C401 567 396 607 392 642C354 654 312 665 266 665C137 665 60 583 60 487C60 374 161 325 225 290C300 250 355 215 355 141C355 68 311 21 235 21C131 21 86 122 71 183L41 176C48 128 61 42 68 21C78 16 93 8 118 0C142 -7 175 -15 216 -15C349 -15 438 69 438 174C438 287 344 333 265 374C186 414 138 449 138 522C138 576 172 631 249 631C336 631 363 562 380 499L409 504Z"/></g><g transform="matrix(.0095,0,0,-0.0095,17.017,3.264)"><use xlink:href="#g190-115"/></g><g transform="matrix(.0095,0,0,-0.0095,21.064,-5.984)"><path id="g54-36" d="M556 236V289H337V504H275V289H56V236H275V-4H337V236H556Z"/></g></svg> to reduce the demand of Sr2+ or Ti3+ vacancy. While Sr-doped Pr will make lattice distortion and transition energy of 4f-5d is very sensitive to crystal electric field changes around Pr atom. Doping different impurities will make electric field distribution around the icon have a different change. It increases energy transfer of 4f-5d transition and improves the luminous intensity of SrTiO3:Pr3+ red phosphor.

Dan Guo

Xiaodong Zhang

Jiangni Yun

Preparation of Compensation Ions Codoped SrTiO3:Pr3+ Red Phosphor with the Sol-Gel Method and Study of Its Luminescence Enhancement Mechanism

Experimental results of the combination of transverse mode selection and active mode-locking with anti-reflection-coated broad area lasers (BALs) are presented. The BALs are subject to feedback from a free-space external Fourier-optical 4<svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-2.34499pt;width:11.0375px;" id="M1" height="16.6625" version="1.1" viewBox="0 0 11.0375 16.6625" width="11.0375">
	
		
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</svg>-setup with a reflective spatial frequency filter in the Fourier-plane for transverse mode selection. Driving the BALs with a high frequency modulated pump current above threshold active longitudinal mode-locking is achieved. Pulse durations as low as 88 ps are obtained, while the Gaussian-like fundamental or a higher order transverse mode up to mode number 5 is selected on purpose. Pulse duration and shape are nearly independent of the selected transverse mode.

Christoph Doering

Henning Fouckhardt

Combination of Transverse Mode Selection and Active Longitudinal Mode-Locking of Broad Area Semiconductor Lasers

We have analyzed the impact of digital and optical signal processing algorithms, that is, Volterra equalization (VE), digital backpropagation (BP), and optical phase conjugation with nonlinearity module (OPC-NM), in next generation 10&#x2009;Gbit/s (also referred to as XG) DP-QPSK long haul WDM (fixed-grid) passive optical network (PON) without midspan repeaters over 120&#x2009;km standard single mode fiber (SMF) link for downstream signals. Due to the compensation of optical Kerr effects, the sensitivity penalty is improved by 2&#x2009;dB by implementing BP algorithm, 1.5&#x2009;dB by VE algorithm, and 2.69&#x2009;dB by OPC-NM. Moreover, with the implementation of NL equalization technique, we are able to get the transmission distance of 126.6&#x2009;km SMF for the 1&#x2009;:&#x2009;1024 split ratio at 5&#x2009;GHz channel spacing in the nonlinear region.

Rameez Asif

Rabeea Basir

Ramshah Ahmad

Signal Processing Algorithms for Down-Stream Traffic in Next Generation 10&#x2009;Gbit/s Fixed-Grid Passive Optical Networks

We propose and design a spiral photonic crystal fiber with elliptical air holes for achieving high birefringence, large nonlinearity, and negative dispersion. The structure is designed using chalcogenide glass (As2S3) for different ellipticity ratios of air holes in the cladding and the effect on various properties is observed. The proposed structure has birefringence of the order 10&#x2212;2, nonlinearity of 26739.42&#x2009;W&#x2212;1&#x2009;m&#x2212;1, and dispersion of &#x2212;1136.69 at 0.85&#x2009;&#x3bc;m. An accurate numerical approach based on finite element method is used for the design and simulation of the structure. Due to high birefringence and negative dispersion, the proposed structure can be used for polarization control and dispersion compensation, respectively.

S. Revathi

Srinivasa Rao Inbathini

Rizwan Ali Saifudeen

Highly Nonlinear and Birefringent Spiral Photonic Crystal Fiber

Highly ordered mesoporous TiO2 modified by CdS, CdSe, and ZnS quantum dots (QDs) was fabricated by successive ionic layer adsorption and reaction (SILAR) method. The quantity of material deposition seems to be affected not only by the employed deposition method but also and mainly by the nature of the underlying layer. The CdS, CdSe, and ZnS QDs modification expands the photoresponse range of mesoporous TiO2 from ultraviolet region to visible range, as confirmed by UV-Vis spectrum. Optimized anode electrodes led to solar cells producing high current densities. Pt, CuS, PbS, and Cu2S have been used as electrocatalysts on counter electrodes. The maximum solar conversion efficiency reached in this work was 1.52&#x25; and was obtained by using Pt electrocatalyst. CuS, PbS, and Cu2S gave high currents and this was in line with the low charge transfer resistances recorded in their case.

Tung Ha Thanh

Dat Huynh Thanh

Vinh Quang Lam

The CdS/CdSe/ZnS Photoanode Cosensitized Solar Cells Basedon Pt, CuS, Cu2S, and PbS Counter Electrodes

We review polarization splitting and rotating photonic devices based on silicon-on-insulator technology platform, focusing on their performance and design criteria. In addition, we present a theoretical investigation and optimization of some rotator and splitter architectures to be employed for polarization diversity circuits. In this context, fabrication tolerances and their influences on device performance are theoretically estimated by rigorous simulations too.

Benedetto Troia

Francesco De Leonardis

Mauro Lanzafame

Tommaso Muciaccia

Giuseppe Grasso

Giovanni Giannoccaro

Carlo Edoardo Campanella

Vittorio M. N. Passaro

Design and Optimization of Polarization Splitting and Rotating Devices in Silicon-on-Insulator Technology

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Advances in OptoElectronics publishes papers on the theory, design, fabrication, and applications of devices and components that convert light into an electrical current or, conversely, an electric current into light.

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Advances in OptoElectronics ceased publication in 2019 and is no longer accepting submissions.

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Advances in OptoElectronics publishes papers on the theory, design, fabrication, and applications of devices and components that convert light into an electrical current or, conversely, an electric current into light.

Advances in OptoElectronics