Photonics West - Optoelectronic Materials and Devices最新文献_第10页

Comparing optical properties of different species of diatoms 比较不同种类硅藻的光学特性

Photonics West - Optoelectronic Materials and Devices Pub Date : 2015-03-16 DOI: 10.1117/12.2078822

C. Maibohm, S. Friis, Yanyan Su, Karsten Rottwitt

{"title":"Comparing optical properties of different species of diatoms","authors":"C. Maibohm, S. Friis, Yanyan Su, Karsten Rottwitt","doi":"10.1117/12.2078822","DOIUrl":"https://doi.org/10.1117/12.2078822","url":null,"abstract":"Diatoms are single cellular algae encapsulated in an external wall of micro-structured porous silica called the frustule. Diatoms are present in all water environments and contribute with 20-25 % of the global primary production of oxygen by photosynthesis. The appearance of the frustule is very species dependent with huge variety in size, shape, and microstructure. We have experimentally investigated optical properties of frustules of several species of diatoms to further understand light harvesting properties together with common traits, effects and differences between the different frustules. We have observed, when incident light interacts with the micro-structured frustule it is multiple diffracted giving rise to wavelength dependent multiple focal points and other optical effects. Experimental results have been simulated and well confirmed by free space FFT propagation routine analysis software. The software uses parameters which are extracted from experimental images as basis for simulation and allows us to extract the influence of the different elements of the frustule. The information could be used both for predicting optical properties of diatoms and by changing frustule parameters, maybe by altering growth conditions of the diatoms tailor their optical properties.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"29 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114023442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Assessment of fiber optic sensors for aging monitoring of industrial liquid coolants 工业液体冷却剂老化监测用光纤传感器的评估

Photonics West - Optoelectronic Materials and Devices Pub Date : 2015-03-16 DOI: 10.1117/12.2079988

C. Riziotis, A. El Sachat, C. Markos, P. Velanas, A. Meristoudi, Aggelos Papadopoulos

{"title":"Assessment of fiber optic sensors for aging monitoring of industrial liquid coolants","authors":"C. Riziotis, A. El Sachat, C. Markos, P. Velanas, A. Meristoudi, Aggelos Papadopoulos","doi":"10.1117/12.2079988","DOIUrl":"https://doi.org/10.1117/12.2079988","url":null,"abstract":"Lately the demand for in situ and real time monitoring of industrial assets and processes has been dramatically increased. Although numerous sensing techniques have been proposed, only a small fraction can operate efficiently under harsh industrial environments. In this work the operational properties of a proposed photonic based chemical sensing scheme, capable to monitor the ageing process and the quality characteristics of coolants and lubricants in industrial heavy machinery for metal finishing processes is presented. The full spectroscopic characterization of different coolant liquids revealed that the ageing process is connected closely to the acidity/ pH value of coolants, despite the fact that the ageing process is quite complicated, affected by a number of environmental parameters such as the temperature, humidity and development of hazardous biological content as for example fungi. Efficient and low cost optical fiber sensors based on pH sensitive thin overlayers, are proposed and employed for the ageing monitoring. Active sol-gel based materials produced with various pH indicators like cresol red, bromophenol blue and chorophenol red in tetraethylorthosilicate (TEOS), were used for the production of those thin film sensitive layers deposited on polymer's and silica's large core and highly multimoded optical fibers. The optical characteristics, sensing performance and environmental robustness of those optical sensors are presented, extracting useful conclusions towards their use in industrial applications.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"9359 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131350621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Nonlinear optical properties of single crystal cadmium magnesium telluride 单晶碲化镉镁的非线性光学性质

Photonics West - Optoelectronic Materials and Devices Pub Date : 2015-03-16 DOI: 10.1117/12.2079877

D. Lombardo, S. Trivedi, S. Guha

引用次数: 5

Theory of an optically driven quantum-dot phonon laser 光驱动量子点声子激光器的理论

Photonics West - Optoelectronic Materials and Devices Pub Date : 2015-03-16 DOI: 10.1117/12.2081870

Leon Droenner, J. Kabuss

引用次数: 1

Laser-assisted manufacturing of micro-optical volume elements for enhancing the amount of light absorbed by solar cells in photovoltaic modules 激光辅助制造微光学体积元件，用于提高光伏组件中太阳能电池的光吸收量

Photonics West - Optoelectronic Materials and Devices Pub Date : 2015-03-16 DOI: 10.1117/12.2077118

G. Peharz, L. Kuna, C. Leiner

{"title":"Laser-assisted manufacturing of micro-optical volume elements for enhancing the amount of light absorbed by solar cells in photovoltaic modules","authors":"G. Peharz, L. Kuna, C. Leiner","doi":"10.1117/12.2077118","DOIUrl":"https://doi.org/10.1117/12.2077118","url":null,"abstract":"The laser-generation of micro-optical volume elements is a promising approach to decrease the optical shadowing of front side metal contacts of solar cells. Focusing a femtosecond laser beam into the volume of the encapsulation material causes a local modification its optical constants. Suchlike fabricated micro-optical elements can be used to decrease the optical shadowing of the front side metallization of c-Si solar cells. Test samples comprising of a sandwich structure of a glass sheet with metallic grid-lines, an Ethylene-vinyl acetate (EVA) encapsulant and another glass sheet were manufactured in order to investigate the optical performance of the volume optics. Transmission measurements show that the shadowing of the metalling grid-lines is substantially decreased by the micro-optical volume elements created in the EVA bulk right above the grid-fingers. A detailed investigation of the optical properties of these volume elements was performed: (i) experimentally on the basis of goniometric measurements, as well as (ii) theoretically by applying optical modelling and optimization procedures. This resulted in a better understanding of the effectiveness of the optical volume elements in decreasing the optical shadowing of metal grid lines on the active cell surfaces. Moreover, results of photovoltaic mini-modules with incorporated micro-optical volume elements are presented. Results of optical simulation and Laser Beam Induced Current (LBIC) experiments show that the losses due to the grid fingers can be reduced by about 50%, when using this fs-laser structuring approach for the fabrication of micro-optical volume elements in the EVA material.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122884500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Five-volt vertically-stacked, single-cell GaAs photonic power converter 五伏垂直堆叠，单电池砷化镓光子功率转换器

Photonics West - Optoelectronic Materials and Devices Pub Date : 2015-03-16 DOI: 10.1117/12.2079824

C. Valdivia, M. Wilkins, B. Bouzazi, A. Jaouad, V. Aimez, R. Arès, D. Masson, S. Fafard, K. Hinzer

引用次数: 36

Design and development of back reflectors for improved light coupling and absorption enhancement in thin MQW solar cells 用于改善薄MQW太阳能电池光耦合和增强吸收的后反射器的设计和开发

Photonics West - Optoelectronic Materials and Devices Pub Date : 2015-03-16 DOI: 10.1117/12.2078669

Wei Wang, A. Freundlich

{"title":"Design and development of back reflectors for improved light coupling and absorption enhancement in thin MQW solar cells","authors":"Wei Wang, A. Freundlich","doi":"10.1117/12.2078669","DOIUrl":"https://doi.org/10.1117/12.2078669","url":null,"abstract":"Optimization of non-planar antireflective coating and back- (or front-) surface texturing are widely studied to further reduce the reflection losses and increase the sunlight absorption path in solar cells. Back reflectors have been developed from perfect mirror to textured mirror in order to further increase light path, which can significantly improve the efficiency and allow for much thinner devices. A Lambertian surface, which has the most random texture, can theoretically raise the light path to 4n2 times that of a smooth surface. It’s a challenge however to fabricate ideal Lambertian texture, especially in a fast and low cost way. In this work we have developed a method to overcome this challenge that combines the use of laser interference lithography (LIL) and selective wet etching. The approach allows for a rapid wafer scale texture processing with sub-wavelength (nano)- scale control of the pattern and the pitch. The technique appears as being particularly attractive for the development of ultra-thin III-V devices, or in overcoming the weak sub-bandgap absorption in devices incorporating quantum dots or quantum wells. Preliminary results on the application of the technique for the development of back reflector for 1-1.3 eV (MQW bearing) GaAs solar cells are presented.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125555132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Circuit-level simulation of transistor lasers and its application to modelling of microwave photonic links 晶体管激光器的电路级仿真及其在微波光子链路建模中的应用

Photonics West - Optoelectronic Materials and Devices Pub Date : 2015-03-16 DOI: 10.1117/12.2079306

S. Iezekiel, A. Christou

引用次数: 1

Suppression of thermal carrier escape and enhanced two-step photon absorption in quantum-dot intermediate-band solar cells with a high-potential barrier 高势势势垒抑制热载流子逸出和增强量子点中带太阳能电池的两步光子吸收

Photonics West - Optoelectronic Materials and Devices Pub Date : 2015-03-16 DOI: 10.1117/12.2081302

S. Asahi, H. Teranishi, N. Kasamatsu, T. Kada, T. Kaizu, T. Kita

引用次数: 1

Demonstration of a 5x5 cm2 self-tracking solar concentrator 5x5 cm2自跟踪太阳能聚光器的演示

Photonics West - Optoelectronic Materials and Devices Pub Date : 2015-03-16 DOI: 10.1117/12.2078775

V. Zagolla, E. Tremblay, C. Moser

{"title":"Demonstration of a 5x5 cm2 self-tracking solar concentrator","authors":"V. Zagolla, E. Tremblay, C. Moser","doi":"10.1117/12.2078775","DOIUrl":"https://doi.org/10.1117/12.2078775","url":null,"abstract":"Solar concentration is using optics in order to minimize the amount of expensive photovoltaic cell material needed. For concentration factors higher than approximately 4, tracking the sun’s position is needed to keep the focal spot on the solar cell. Based on recent developments using a waveguide slab to concentrate sunlight we propose and demonstrate a light responsive, self-tracking solar concentrator. Using a phase change material acting at the focal spot, it is possible to maintain efficient coupling into the waveguide, up to an angular range of +/- 20 degrees. The system uses the unused infrared part of the solar spectrum as energy for the phase change actuator to achieve its high acceptance angle. With a spectrally matched custom silicon solar cell attached to the waveguide slab, in which light is coupled, the visible part of the solar spectrum can be efficiently converted to electricity. A proof-of-concept single lens device was demonstrated in our previous work. Here we extend the principle to a 3x3 lens array demonstration device. The current demonstration device features an acceptance angle of +/- 16 degrees and an effective concentration factor of up to 20x.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"9358 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130777029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1