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Optics Express

Min-Ho Shin, Hyo-Jun Kim, Young-Joo Kim
We proposed an optical simulation model for the quantum dot (QD) nanophosphor based on the mean free path concept to understand precisely the optical performance of optoelectronic devices. A measurement methodology was also developed to get the desired optical characteristics such as the mean free path and absorption spectra for QD nanophosphors which are to be incorporated into the simulation. The simulation results for QD-based white LED and OLED displays show good agreement with the experimental values from the fabricated devices in terms of spectral power distribution, chromaticity coordinate, CCT, and CRI...
February 20, 2017: Optics Express
Ebuka S Arinze, Botong Qiu, Nathan Palmquist, Yan Cheng, Yida Lin, Gabrielle Nyirjesy, Gary Qian, Susanna M Thon
Colloidal quantum dots (CQDs), are a promising candidate material for realizing colored and semitransparent solar cells, due to their band gap tunability, near infrared responsivity and solution-based processing flexibility. CQD solar cells are typically comprised of several optically thin active and electrode layers that are optimized for their electrical properties; however, their spectral tunability beyond the absorption onset of the CQD layer itself has been relatively unexplored. In this study, we design, optimize and fabricate multicolored and transparent CQD devices by means of thin film interference engineering...
February 20, 2017: Optics Express
Zhongqiu Sun, Di Wu, Yunfeng Lv
The optical scattering property of a target is the essential signal for passive remote sensing. In this study, we performed the photopolarimetric measurements of a manmade target in the wavelength range of 400-1000 nm over the hemispherical directions using the Northeast Normal University Laboratory Goniospectrometer System (NENULGS). We discussed the influence of the absorption of a polarizer on the measured Stokes parameters, and used the BRF (bidirectional reflectance factor) and BPRF (bidirectional polarized reflectance factor) to characterize the scattering property of our sample at selected wavelengths...
February 20, 2017: Optics Express
Vincent Mariage, Jacques Pelon, Frédéric Blouzon, Stéphane Victori, Nicolas Geyskens, Nadir Amarouche, Christine Drezen, Antoine Guillot, Michel Calzas, Magali Garracio, Nicolas Wegmuller, Nathalie Sennéchael, Christine Provost
The in situ tests of first ever autonomous aerosol and cloud backscatter LIDAR (light detection and ranging) systems implemented on buoys for Arctic observations has been achieved in 2015 within the French EQUIPEX IAOOS project. The environmental and operational constraints were met by adopting a concept of a fibered microjoule lidar system using a laser diode. Two systems have been developed with and without polarization analysis capability. A specific optical design was used for polarization discrimination...
February 20, 2017: Optics Express
Vladimir Oliker
The SQM is a versatile methodology for designing freeform optics for irradiance redistribution. Recently it has often been applied in design of freeform lenses, mirrors and diffractive optical elements. Still, many questions regarding theory and performance of optics designed with the SQM are open. Here we investigate theoretically plano-freeform refractive lenses designed with the SQM when an incident collimated beam must be transformed into a beam illuminating with prescribed irradiances a large number of pixels on a flat screen...
February 20, 2017: Optics Express
Xiao-Jing Han, Si-Bo Duan, Zhao-Liang Li
An analysis of the atmospheric impact on ground brightness temperature (Tg) is performed for numerous land surface types at commonly-used frequencies (i.e., 1.4 GHz, 6.93 GHz, 10.65 GHz, 18.7 GHz, 23.8 GHz, 36.5 GHz and 89.0 GHz). The results indicate that the atmosphere has a negligible impact on Tg at 1.4 GHz for land surfaces with emissivities greater than 0.7, at 6.93 GHz for land surfaces with emissivities greater than 0.8, and at 10.65 GHz for land surfaces with emissivities greater than 0.9 if a root mean square error (RMSE) less than 1 K is desired...
February 20, 2017: Optics Express
Sergey V Kravchenko, Egor V Byzov, Mikhail A Moiseev, Leonid L Doskolovich
The development of LED secondary optics for road illumination is quite a challenging problem. Optical elements developed for this kind of application should have maximal efficiency, provide high luminance and illuminance uniformity, and meet many other specific requirements. Here, we demonstrate that the usage of the supporting quadric method modification enables generating free-form optical solution satisfying all these requirements perfectly. As an example, two optical elements for different roadway types are computed, manufactured by injection molding, and then measured in a photometry bench...
February 20, 2017: Optics Express
F-J Haug, M Bräuninger, C Ballif
We apply a Fourier-scattering model to describe light scattering in solar cells with textured surfaces. For the size and inclination angle of typical micro-textures, scattering may occur into large angles. This makes the model prone to paraxial errors. We present a non-paraxial formulation and discuss the transition from the domain of refraction at large facets to scattering at small features.
February 20, 2017: Optics Express
Xiaodong Zhang, Shuangyan He, Afshin Shabani, Peng-Wang Zhai, Keping Du
In examining the dependence of the sea surface reflectance of skylight ρs on sky conditions, wind speed, solar zenith angle, and viewing geometry, Mobley [Appl. Opt.38, 7442 (1999).10.1364/AO.38.007442] assumed ρs is independent of wavelength. Lee et al. [Opt. Express18, 26313 (2010).10.1364/OE.18.026313] showed experimentally that ρs does vary spectrally due to the spectral difference of sky radiance coming from different directions, which was ignored in Mobley's study. We simulated ρs from 350 nm to 1000 nm by explicitly accounting for spectral variations of skylight distribution and Fresnel reflectance...
February 20, 2017: Optics Express
Lidia Galdino, Daniel Semrau, Domaniç Lavery, Gabriel Saavedra, Cristian B Czegledi, Erik Agrell, Robert I Killey, Polina Bayvel
This paper investigates the impact of transceiver noise on the performance of digital back-propagation (DBP). A generalized expression to estimate the signal-to-noise ratio (SNR) obtained using DBP in the presence of transceiver noise is described. This new expression correctly accounts for the nonlinear beating between the transceiver noise and the signal in the optical fiber transmission link. The transceiver noise-signal nonlinear beating has been identified as the main reason for the discrepancy between predicted and practical performance of DBP; which has not been previously suggested...
February 20, 2017: Optics Express
Domaniç Lavery, Robert Maher, Gabriele Liga, Daniel Semrau, Lidia Galdino, Polina Bayvel
The Gaussian noise model is used to estimate the performance of three digital nonlinearity compensation (NLC) algorithms in C-band, long-haul, optical fiber transmission, when the span length and NLC bandwidth are independently varied. The algorithms are receiver-side digital backpropagation (DBP), transmitter-side DBP (digital precompensation), and Split NLC (an equal division of DBP between transmitter and receiver). For transmission over 100×100 km spans, the model predicts a 0.2 dB increase in SNR when applying Split NLC (versus DBP) to a single 32 GBd channel (from 0...
February 20, 2017: Optics Express
Magnus Karlsson, Nikola Alic, Sethumadhavan Chandrsekhar, Antonio Mecozzi
The authors introduce the feature issue on nonlinearity mitigation for coherent transmission systems.
February 20, 2017: Optics Express
Aya Nozaki, Masaya Mitobe, Fumio Okuyama, Yuji Sakamoto
Electro-holography can display images without inducing fatigue and three-dimensional (3D) sickness, i.e., visual discomfort due to viewing a stereoscopic display. Thus, this technology is expected to be applied to 3D media. However, there are no studies that have shown the agreement between the dynamic responses of accommodation and vergence to the reconstructed images of electro-holography and those to the real targets. This paper describes the measurement results of these responses using a developed system that can simultaneously measure the dynamic responses of accommodation and vergence...
February 20, 2017: Optics Express
Mingwei Lei, Chengyin Wu, An Zhang, Qihuang Gong, Hongbing Jiang
Nitrogen molecular ions (N<sub>2</sub> <sup>+</sup>) in air plasma pumped by femtosecond laser pulses give rise to superradiant emission at 391.4 nm in the presence of an external seed pulse at proper wavelength. Due to the transient alignment of the nitrogen molecular ions, the superradiance signal presents a strong modulation as a function of the temporal delay between the pump and the seed pulses. Through Fourier transformation with high frequency resolution, we distinguished the contribution of the finely separated rotation levels of the upper and lower states...
February 20, 2017: Optics Express
Ke Xu, Qiong Wu, Yongqiang Xie, Ming Tang, Songnian Fu, Deming Liu
The 2-μm optical band has gained much attention recently due to its potential applications in optical fiber communication systems. One constraint in this wavelength region is that the electrical bandwidth of components like modulators and photodetectors is limited by the immature manufacturing technologies. Here we experimentally demonstrated the high-speed signal generation and transmission under bandwidth-constrained scenario at 2-μm. It is enabled by the direct-detection optical filter bank multicarrier (FBMC) modulation technique with constant amplitude zero autocorrelation (CAZAC) equalization...
February 20, 2017: Optics Express
Tianwei Jiang, Ruihuan Wu, Song Yu, Dongsheng Wang, Wanyi Gu
Traditional microwave photonic systems cannot implement frequency up-conversion with phase tunable capability, which plays an important role for phase array beamforming. Here, a method that can implement both upconversion and downconversion with a broadband full-degree phase-shift capability by constructing an optical path with a Hilbert transform function is presented. Owing to the Hilbert transform path, the dual-drive Mach-Zehnder modulator (DMZM) bias information, which initially influences the amplitudes of the output signals, are transferred to their phases...
February 20, 2017: Optics Express
Heyjin Son, Da-Hye Choi, Gun-Sik Park
In terahertz transmission spectroscopy, there is a typical problem of thickness uncertainty, which hampers to determine precise optical parameters of samples. In order to resolve this experimental problem, a method optimizing sample thickness using singly subtractive Kramers-Kronig relations is proposed. For tens of micrometers thick water samples, we improved the accuracy of sample thickness by an order of magnitude (up to sub-micrometer) using the algorithm leading to obtain precise optical parameters of water...
February 20, 2017: Optics Express
Gyujeong Hwang, Soner Balci, M Zeki Güngördü, Alex Maleski, Joseph Waters, Sunjong Lee, Sangjun Choi, Kyoungkook Kim, Soohaeng Cho, Seongsin M Kim
Highly stable and flexible transparent electrodes are fabricated based on silver nanowires (AgNWs) on both polyethylene-terephthalate (PET) and polyimide (PI) substrates. Terahertz time domain spectroscopy (THz-TDS) was utilized to probe AgNW films while bended with a radius 5 mm to discover conductivity of bended films which was further analyzed through Drude-Smith model. AgNW films experience little degradation in conductivity (<3%) before, after, and during 1000 bending cycles. Highly stable AgNW flexible electrodes have broad applications in flexible optoelectronic and electronic devices...
February 20, 2017: Optics Express
Ying Qiu, Xiang Li, Ming Luo, Daigao Chen, Jiamin Wang, Jing Xu, Qi Yang, Shaohua Yu
We experimentally demonstrate on-chip mode-selective wavelength conversions based on the degenerate four-wave mixing (FWM) nonlinear effect in a few-mode silicon waveguide. A multimode waveguide with tapered directional coupler based mode (de)multiplexers is designed and fabricated. Using signals with advanced modulation formats all-optical wavelength conversions of 102.6-Gb/s OFDM-QPSK signals are verified. Experimental results show that only small optical signal-to-noise ratio (OSNR) penalties are observed after wavelength conversion of both modes, which are less than 2 dB for OFDM-QPSK at 7% forward error correction (FEC) threshold...
February 20, 2017: Optics Express
Guang-Ling Cheng, Ai-Xi Chen
We show the effect of squeezed vacuum on laser-induced grating in a weak standing-wave-driving two-level atomic system. Using the optical Bloch equation and the Floquet harmonic expansion, we obtain the linear response of the medium with respect to the probe field, which determines the transmission spectrum and diffraction intensity. At the presence of the squeezing, the grating with large intensity both in the first- and higher-order directions can be obtainable even though the driving is relatively weak. The responsible mechanism is due to squeezing-induced gain accompanied by the large dispersion...
February 20, 2017: Optics Express
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