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2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS)最新文献

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Tolerance to in-band crosstalk of virtual carrier-assisted direct detection multi-band OFDM systems 虚拟载波辅助直接检测多波段OFDM系统带内串扰容忍度
2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS) Pub Date : 2016-11-25 DOI: 10.5220/0005743300310037
B. Pinheiro, J. Rebola, A. Cartaxo
{"title":"Tolerance to in-band crosstalk of virtual carrier-assisted direct detection multi-band OFDM systems","authors":"B. Pinheiro, J. Rebola, A. Cartaxo","doi":"10.5220/0005743300310037","DOIUrl":"https://doi.org/10.5220/0005743300310037","url":null,"abstract":"The tolerance to in-band crosstalk of virtual carrier (VC)-assisted direct detection (DD) multi-band orthogonal frequency division multiplexing (MB-OFDM) system is assessed numerically through Monte-Carlo simulation and considering a single interferer. The influence of the virtual carrier-to-band power ratio (VBPR) and the virtual carrier-to-band gap (VBG) of the interferer on the in-band tolerance is also studied. We show that, for interferers with the same VBG as the selected signal, the increase of the VBPR of the interferer leads to lower optical signal-to-noise ratio (OSNR) penalties. The increase of the VBG of the interferer with central frequency different from the selected signal also leads to lower OSNR penalties. When the central frequencies of the interferer and selected bands are the same, the variation VBG of the interferer can lead to 11 dB less tolerance to in-band crosstalk of the VC-assisted DD OFDM system.","PeriodicalId":222009,"journal":{"name":"2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125887701","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
Two-photon excitation of hydrogen atom by sub-femtoseconds electromagnetic pulses 亚飞秒电磁脉冲对氢原子的双光子激发
2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS) Pub Date : 2016-11-24 DOI: 10.5220/0005650300510054
V. Astapenko, S. Sakhno
{"title":"Two-photon excitation of hydrogen atom by sub-femtoseconds electromagnetic pulses","authors":"V. Astapenko, S. Sakhno","doi":"10.5220/0005650300510054","DOIUrl":"https://doi.org/10.5220/0005650300510054","url":null,"abstract":"The development of methods of generation of ultrashort pulses (USP) of femto- and attosecond duration ranges with controlled parameters necessitates the theoretical study of features of their interaction with a matter. Among such features that do not exist in case of “long” pulses should first of all be the nonlinear dependence of the photoprocess probability W on the USP duration as well as the dependence on the carrier phase with respect to the pulse envelope. It should be noted that if the dependence of the probability W on the phase manifests itself either only for very short pulses, when ωt < 1 (w is carrier frequency of the pulse, t its duration), or in case of a nonlinear photoprocess, the function W(t) can differ from a linear function in the limit ωt > 1 too for fields of moderate strength, when the perturbation theory is applicable. The present work is dedicated to the theoretical analysis of two-photon excitation of hydrogen atom in a discrete energy spectrum by ultrashort electromagnetic pulses of femto- and subfemtosecond ranges of durations. As examples, excitation of hydrogen atom from the ground state to excited states with a zero orbital moment is considered.","PeriodicalId":222009,"journal":{"name":"2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114472223","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
Effect of dispersive reflectivity on the stability of gap solitons in systems with separated Bragg grating and nonlinearity 色散反射率对分离布拉格光栅和非线性系统中间隙孤子稳定性的影响
2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS) Pub Date : 2016-11-24 DOI: 10.5220/0005651602310235
Tanvir Ahmed, J. Atai
{"title":"Effect of dispersive reflectivity on the stability of gap solitons in systems with separated Bragg grating and nonlinearity","authors":"Tanvir Ahmed, J. Atai","doi":"10.5220/0005651602310235","DOIUrl":"https://doi.org/10.5220/0005651602310235","url":null,"abstract":"The existence and stability of quiescent solitons in a dual core optical medium, where the one core has only Kerr nonlinearity while the other has Bragg grating and dispersive reflectivity are investigated. Three spectral gaps are identified in the systems linear spectrum, in which both lower and upper band gaps overlap with one branch of the continuous spectrum for all values of normalized group velocity c in the linear core; and, the central band gap remains a genuine bandgap. Soliton solutions exist only in the lower and upper gaps. In the absence of dispersive reflectivity, stable solitons are only found in the upper bandgap. However, introduction of dispersive reflectivity significantly alters the stability characteristics of solitons and results in the stabilization of solitons in a portion of the lower bandgap.","PeriodicalId":222009,"journal":{"name":"2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115353052","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
An intelligent speckle reduction algorithm for optical coherence tomography images 光学相干层析成像的智能散斑减少算法
2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS) Pub Date : 2016-11-23 DOI: 10.5220/0005744700380043
S. Adabi, S. Conforto, Anne Clayton, A. Podoleanu, A. Hojjat, Mohammad R. N. Avanaki
{"title":"An intelligent speckle reduction algorithm for optical coherence tomography images","authors":"S. Adabi, S. Conforto, Anne Clayton, A. Podoleanu, A. Hojjat, Mohammad R. N. Avanaki","doi":"10.5220/0005744700380043","DOIUrl":"https://doi.org/10.5220/0005744700380043","url":null,"abstract":"Optical Coherence Tomography (OCT) offers three dimensional images of tissue microstructures. Although OCT imaging offers a promising high resolution method, due to the low coherent light source used in the configuration of OCT, OCT images suffers from an artefact called, speckle. Speckle deteriorates the image quality and effects image analysis algorithm such as segmentation and pattern recognition. We present a novel and intelligent speckle reduction algorithm to reduce speckle based on an ensemble framework of Multi-Layer Perceptron (MLP) neural networks. We tested the algorithm on images of retina obtained from a spectrometer-based Fourier-domain OCT system operating at 890 nm, and observed considerable improvement in the signal-to-noise ratio and contrast of the images.","PeriodicalId":222009,"journal":{"name":"2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132924077","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: 32
Performance analysis of 1310/1490 Nm demultiplexer based on multimode interference coupler for PON 基于多模干扰耦合器的PON 1310/1490 Nm解复用器性能分析
2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS) Pub Date : 2016-11-22 DOI: 10.5220/0005649502230226
D. Chack, V. Kumar, D. Singh
{"title":"Performance analysis of 1310/1490 Nm demultiplexer based on multimode interference coupler for PON","authors":"D. Chack, V. Kumar, D. Singh","doi":"10.5220/0005649502230226","DOIUrl":"https://doi.org/10.5220/0005649502230226","url":null,"abstract":"The design and analysis of a 1310/1490-nm demultiplexer based on Multimode Interference (MMI) coupler for Passive Optical Networks (PON) has been studied in this paper. Numerical simulations with finite difference Beam Propagation Method (BPM) have been utilized to optimize the operation of the proposed demultiplexer. The device has been designed with optimized width and MMI length and its analysis has been done based on extinction ratio and Insertion loss. Restricted interference has been used to reduce the size of the device. The device has been solely designed using 1310 nm as upstream and 1490 nm as downstream of data for Passive Optical Network communication system.","PeriodicalId":222009,"journal":{"name":"2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS)","volume":"321 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132775428","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
Depth resolution in coherent hemodynamics spectroscopy 相干血流动力学光谱中的深度分辨率
2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS) Pub Date : 2016-11-22 DOI: 10.5220/0005792101850191
A. Sassaroli, Xuan Zang, K. Tgavalekos, S. Fantini
{"title":"Depth resolution in coherent hemodynamics spectroscopy","authors":"A. Sassaroli, Xuan Zang, K. Tgavalekos, S. Fantini","doi":"10.5220/0005792101850191","DOIUrl":"https://doi.org/10.5220/0005792101850191","url":null,"abstract":"Coherent hemodynamics spectroscopy (CHS) is a novel method based on the frequency-resolved study of induced hemodynamic oscillations in living tissues. Approaches to induce hemodynamic oscillations in human subjects include paced breathing and cyclic thigh cuff inflation. Such induced hemodynamic oscillations result in coherent oscillations of oxy-, deoxy-, and total hemoglobin concentrations in tissue, which can be measured with near-infrared spectroscopy (NIRS). The novel aspect of CHS is to induce hemodynamic oscillations at multiple frequencies in order to obtain frequency-resolved spectra of coherent hemodynamics. A dedicated mathematical model recently developed by our group, can translate the phase and amplitude spectra of these hemodynamic oscillations into physiological parameters such as capillary and venous transit times, and the autoregulation cutoff frequency. A typical method used in near-infrared tissue spectroscopy to measure oscillations of hemoglobin concentrations is based on the modified Beer-Lambert law, which does not allow for the discrimination of hemodynamic oscillations occurring in the scalp from those occurring in the brain cortex. In this work, we show preliminary results obtained by using diffusion theory for a two-layered medium, so that the hemodynamic oscillations obtained for the first and second layer are assigned to hemodynamic oscillations occurring in the scalp/skull and brain cortex tissues, respectively.","PeriodicalId":222009,"journal":{"name":"2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS)","volume":"230 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128590415","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
Low order aberrations compensation by direct adjustment of the reflective beam shaper in slab laser 平板激光器反射光束整形器直接调节的低阶像差补偿
2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS) Pub Date : 2016-11-22 DOI: 10.5220/0005736501130118
Liu Wenguang, Zhou Qiong, Wang Gang, Xie Kun, Yan Baozhu, Xi Fengjie
{"title":"Low order aberrations compensation by direct adjustment of the reflective beam shaper in slab laser","authors":"Liu Wenguang, Zhou Qiong, Wang Gang, Xie Kun, Yan Baozhu, Xi Fengjie","doi":"10.5220/0005736501130118","DOIUrl":"https://doi.org/10.5220/0005736501130118","url":null,"abstract":"A direct method for compensation of low order aberrations with large PV value was presented in this paper. In which, the relationship between the optical layout parameters and the output aberration coefficients were derived by ray matrix method. Then, the adjustment parameters calculated by the equations were used to change the optical layout parameters to compensate the low order aberrations with defocus and astigmatism. The effectiveness of this method was verified by simulations based on the optical models built in a optical design software. It shows that the low order aberrations can be accurately compensated to a level below 0.5λ by the direct method.","PeriodicalId":222009,"journal":{"name":"2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115003085","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
Nanosecond pulse generation near 1.55 micron in the all-fiber figure-eight mode-lock laser with passive nonlinear loop mirror 无源非线性环镜全光纤八字形锁模激光器在1.55微米附近产生纳秒脉冲
2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS) Pub Date : 2016-11-22 DOI: 10.5220/0005687403050310
S. Aleshkina, M. Bubnov, M. Likhachev
{"title":"Nanosecond pulse generation near 1.55 micron in the all-fiber figure-eight mode-lock laser with passive nonlinear loop mirror","authors":"S. Aleshkina, M. Bubnov, M. Likhachev","doi":"10.5220/0005687403050310","DOIUrl":"https://doi.org/10.5220/0005687403050310","url":null,"abstract":"Figure-eight mode-lock all-fiber laser based on a passive nonlinear loop mirror emitting nanosecond pulses at wavelength near 1.55 μm has been realized for the first time. Influence of the total laser dispersion on output characteristics of the laser has been studied. It is revealed that the main problem of utilization fibers with anomalous dispersion inside the passive nonlinear loop mirror is generation of low-energy optical solitons accompanied with nanosecond pulse break up. Solutions of this problem are discussed and stable laser schemes (i.e. all-polarization maintaining) are realized.","PeriodicalId":222009,"journal":{"name":"2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121998156","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
Birefringence creation by solar light: A new approach to the development of solar cells with azobenzene materials 太阳能光产生双折射:偶氮苯材料太阳能电池发展的新途径
2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS) Pub Date : 2016-11-21 DOI: 10.5220/0005843103650368
Pedro F Farinha, S. Sério, P. Ribeiro, M. Raposo
{"title":"Birefringence creation by solar light: A new approach to the development of solar cells with azobenzene materials","authors":"Pedro F Farinha, S. Sério, P. Ribeiro, M. Raposo","doi":"10.5220/0005843103650368","DOIUrl":"https://doi.org/10.5220/0005843103650368","url":null,"abstract":"The conversion of solar energy into electricity is one of the viable alternatives regarding energy demand and sustainability. This work shows that novel energy storage devices can be developed by using materials containing highly polarizable molecules as poly{1-(4-(3-carboxy-4-hydroxy-phenylazo) benzenesulfonamido) −1,2-ethanediyl, sodium salt} (PAZO). In the present case, layer-by-layer (LbL) of PAZO and poly(allylamine hydrochloride) (PAH) thin films were prepared and the creation and relaxation of photoinduced birefringence were characterized. These results demonstrate that birefringence can be induced in these films by visible light with a spectrum similar to solar light. Comparing the characteristics parameters of birefringence creation and relaxation, it was seen that the writing birefringence characteristic time, with a value of 1.4 hours, is quite slower than the obtained with laser beam but the relaxation characteristic time is of the order of 7 days. In addition, the birefringence value is proportional to the amount of azo-groups in the sample. These preliminary results allows us conclude that solar devices based in that principle can be studied, namely, the conversion of the oriented dipoles stored energy in power.","PeriodicalId":222009,"journal":{"name":"2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126434455","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: 4
New materials for photon counting avalanche photodiodes 光子计数雪崩光电二极管的新材料
2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS) Pub Date : 2016-11-20 DOI: 10.5220/0005656802360240
J. Blažej
{"title":"New materials for photon counting avalanche photodiodes","authors":"J. Blažej","doi":"10.5220/0005656802360240","DOIUrl":"https://doi.org/10.5220/0005656802360240","url":null,"abstract":"The experimental results acquired on avalanche photodiodes based on III-V semiconductor materials and operated as single photon counters with picosecond timing resolution are reported. The semiconductor structures fabricated on the basis of GaAs, GaP and GaAsP have been operated in a Geiger mode and employed in a photon counting experiment at the wavelengths from near ultraviolet to near infrared. The dark count rates, photon counting sensitivity and timing resolution have been measured for the experimental diode samples.","PeriodicalId":222009,"journal":{"name":"2016 4th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133256844","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
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