2014
2014
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Record 385 of
Title:Road surface condition sensor based on scanning detection of backward power
Author(s):Xu, Songsong(1); Ruan, Chi(1); Feng, Lili(1)Source: Chinese Optics Letters Volume: 12 Issue: 5 DOI: 10.3788/COL201412.050801 Published: May 2014Abstract:A method of detecting dry, icy and wet road surface conditions based on scanning detection of single wavelength backward power is proposed in this letter. The detector is used to receive the backward scattered power which changes with the incidence angle. The relationship between backward power and incidence angle is used to find out the effective angle range and distinguish method. Experiment and simulation show that it is feasible to classify these three conditions within incidence angle of 5.3 degree. ? 2014 Chinese Optics Letters.Accession Number: 20142717903543 -
Record 386 of
Title:All-fiber laser simultaneously delivering multi-wavelength solitons
Author(s):Yun, L.(1)Source: Optics Communications Volume: 322 Issue: DOI: 10.1016/j.optcom.2014.02.007 Published: July 1, 2014Abstract:All-fiber triple-wavelength laser mode-locked by a nonlinear amplifier loop mirror is proposed and demonstrated experimentally for the first time to author's best knowledge. By means of chirped fiber Bragg gratings in the intra-cavity and extra-cavity, three kinds of solitons with different wavelengths are simultaneously delivered from the proposed laser. The central wavelengths of solitons are 1539.5, 1549.5, and 1559.5 nm with the pulse durations of 6.2, 4.2, and 5 ps and the spectral bandwidths of 0.4, 0.7, and 0.5 nm, respectively. The experimental observations show that the all-fiber triple-wavelength laser is very stable in the long-term operation and is convenient for practical applications. ? 2014 Elsevier B.V.Accession Number: 20141017427504 -
Record 387 of
Title:Very large mode area optical fiber with complex ring cores
Author(s):Zhu, Yonggang(1); Duan, Kailiang(1); Yang, Hening(1); Zhao, Baoyin(1); Zhao, Wei(1)Source: Optik Volume: 125 Issue: 23 DOI: 10.1016/j.ijleo.2014.08.083 Published: December 1, 2014Abstract:A novel kind of single-mode large-mode-area optical fiber is presented in this paper. The proposed fiber core is composed of high-index central rod and the surrounding multilayer rings. The mode characteristics are discussed considering the fiber structure parameters. The calculation results show that the proposed fiber possesses extreme large mode area of 2975 μm2 with single mode operation at the wavelength of 1.08 μm. Even larger mode area of the complex ring core fiber with single mode output can be achieved by coiling the fiber, due to the significant difference of bending loss between the fundamental mode and the higher-order transverse modes. Such fibers are expected to find applications in the field of fiber lasers and amplifiers. ? 2014 Elsevier GmbH. All rights reserved.Accession Number: 20144700220471 -
Record 388 of
Title:Lensless ghost imaging experiments in three different configurations
Author(s):Xue, Yu-Lang(1); Wan, Ren-Gang(1); Feng, Fei(1); Yao, Yin-Ping(1); Zhang, Tong-Yi(1)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 43 Issue: 8 DOI: 10.3788/gzxb20144308.0823006 Published: August 1, 2014Abstract:To achieve stand-off sensing applications, ghost imaging experiments with pseudothermal light were performed from transmissive to reflective cases. First, ghost images of a transmissive double-slit aperture were retrieved in a setup that both the reference beam and signal beam were collected with two different regions of a single CCD. Then a CCD and a separate bucket detector were used to record the light intensity information of the reference beam and the signal beam, respectively. By calculating the intensity correlation function of the signal beam with no spatial light distribution and the spatial dependent reference beam that does not interact with the object, ghost images of a transmissive object and a reflective object were achieved. In order to design and develop prototype systems field applicable, detailed experimental investigations were performed to compare the effect of system parameters on the quality of imaging in the transmission configuration. The results show that enough high power of light source, large sample numbers, and proper exposure time and spatial frequency bandwidth can lead to ghost image with good resolution and visibility.Accession Number: 20143900077225 -
Record 389 of
Title:Simultaneous picosecond and femtosecond solitons delivered from a nanotube-mode-locked all-fiber laser
Author(s):Han, D.D.(1); Liu, X.M.(1); Cui, Y.D.(1); Wang, G.X.(1); Zeng, C.(1); Yun, L.(1)Source: Optics Letters Volume: 39 Issue: 6 DOI: 10.1364/OL.39.001565 Published: March 15, 2014Abstract:We propose a compact nanotube-mode-locked all-fiber laser that can simultaneously generate picosecond and femtosecond solitons at different wavelengths. The pulse durations of picosecond and femtosecond solitons are measured to be ?10.6 ps and ?466 fs, respectively. Numerical results agree well with the experimental observations and clearly reveal that the dynamic evolutions of the picosecond and femtosecond solitons are qualitatively distinct in the intracavity. Our study presents a simple, stable, low-cost, and dual-scale ultrafast-pulsed laser source suitable for practical applications in optical communications. ? 2014 Optical Society of America.Accession Number: 20141517549031 -
Record 390 of
Title:Analysis of Lorentzian line shape function broadened by non-sinusoidal wavelength modulation
Author(s):Sun, You-Qun(1); Wang, Yun-Tao(1); Ruan, Chi(1); Xu, Song-Song(1)Source: Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis Volume: 34 Issue: 3 DOI: 10.3964/j.issn.1000-0593(2014)03-0597-04 Published: March 2014Abstract:In the present work, the Fourier analysis of Lorentzian line shape broadened by non-sinusoidal wavelength modulation was investigated, in which the third order and above harmonic items were ignored. The analytical expression of n-order Fourier coefficient was brought out, where a variable K named harmonic distortion to characterize the ratio of the second harmonic to the first harmonic was introduced. Numerical simulations based on the cases of K>0.01 and K0.01, the effect of different depths of modulation on the odd and even order harmonic amplitude curve is significant. And the numerical simulation shows there exists an optimum value of modulation depth which could minimize the impact of the harmonic distortion, and both large K value and small K value would cause a great error. The conclusion of this work could be applied in error analysis of wavelength modulation spectroscopy system. And the results are helpful to deepening understanding of WMS and would be the important reference for some kind of frequency stabilization technology in laser instrument.Accession Number: 20141217481856 -
Record 391 of
Title:Experimental and theoretical investigations of a tunable dissipative soliton fiber laser
Author(s):Han, D.D.(1)Source: Applied Optics Volume: 53 Issue: 32 DOI: 10.1364/AO.53.007629 Published: November 10, 2014Abstract:Atunable dissipative soliton fiber laser based on carbon nanotubes and the nonlinear polarization rotation (NPR) technique has been investigated experimentally and numerically for the first time to the author's best knowledge. The laser proposed delivers strongly chirped solitons with pulse duration of ～220 ps and a spectral width of ～5.6 nm. With the NPR-related filtering effect, the output pulses are wavelength tunable over the range from 1566 to 1593nmby adjusting the polarization controller (PC).Numerical results are in good agreement with experimental observations and clearly reveal that the tunable mode-locking operation is attributed to the variation of phase delay caused by the PCs. ? 2014 Optical Society of America.Accession Number: 20144600208519 -
Record 392 of
Title:Calibration of stiffness of optical tweezers in three dimensions with power spectral density method
Author(s):Liang, Yan-Sheng(1); Yao, Bao-Li(1); Lei, Ming(1); Yu, Xiang-Hua(1); Yan, Shao-Hui(1); Yang, Yan-Long(1); Dan, Dan(1); Gao, Peng(1); Min, Jun-Wei(1); Ye, Tong(1)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 43 Issue: 5 DOI: 10.3788/gzxb20144305.0535001 Published: May 2014Abstract:An optical tweezers system which can accurately and quickly calibrate the stiffness of optical tweezers in three dimensions was set up combined with quadrant photodiode detector and power spectral density method. The limited Brownian motion of the trapped particle was recorded by a quadrant photodiode detector, and the stiffness of optical tweezers was calibrated by power spectral density method. The relations of the laser power with the stiffness of a 0.97 μm-diameter silica bead and of the 1 μm-diameter PMMA bead were investigated. The results indicate that the stiffness is proportional to the laser power at the range from 50 mW to 120 mW of laser power for a 0.97 μm-diameter silica bead and at the range from 80 mW to 130 mW for a 1 μm-diameter PMMA bead. This system can be used as a precise force measuring tool for microscopic investigation in biology, physics, etc.Accession Number: 20142617873998 -
Record 393 of
Title:Observation of vector- and scalar-pulse in a nanotube-mode-locked fiber laser
Author(s):Yun, Ling(1); Liu, Xueming(1); Han, Dongdong(1)Source: Optics Express Volume: 22 Issue: 5 DOI: 10.1364/OE.22.005442 Published: March 10, 2014Abstract:We report the experimental observations of vector pulse trapping and scalar dissipative soliton in a compact nanotube-mode-locked all-fiber laser for the first time to our best knowledge. The vector pulse exhibits a smooth Gaussian spectral profile without any sidebands. Although two orthogonally polarized components of the vector pulse have different central wavelengths, they copropagate as a unit in the laser cavity with the same speed. The scalar dissipative soliton shows a rectangular spectrum with pulse duration of ～13 ps, and can be compressed to ～320 fs external to the cavity. This flexible laser provides stable, ultrashort vector- and scalarpulsed sources, which is convenient and attractive for practical applications. ? 2014 Optical Society of America.Accession Number: 20141317504899 -
Record 394 of
Title:Plasmon-induced transparency in metal-insulator-metal waveguide side-coupled with multiple cavities
Author(s):Guo, Jing(1)Source: Applied Optics Volume: Issue: 8 DOI: 10.1364/AO.53.001604 Published: March 10, 2014Abstract:We have demonstrated the analogue of electromagnetically induced transparency (EIT) in the metal-insulator-metal plasmonic waveguide, which consists of a bus waveguide side-coupled with a series of slot cavities. By finite-difference time-domain simulations, it is found that the resonance wavelength of the slot cavity can be controlled by adjusting the length of the cavity. Moreover, the EIT-like response is strongly dependent on the coupling separation between the corresponding adjacent cavities. Multiple-peak plasmon-induced transparency can be realized by cascading multiple cavities with different lengths and suitable cavity-cavity separations. This ultracompact plasmonic waveguide system may find important applications for multichannel plasmonic filter, nanoscale optical switching, and slow-light devices in highly integrated optical circuits and networks. ? 2014 Optical Society of America.Accession Number: 20142400000977 -
Record 395 of
Title:Mid-infrared Raman amplification and wavelength conversion in dispersion engineered silicon-on-sapphire waveguides
Author(s):Wang, Zhaolu(1); Liu, Hongjun(1); Huang, Nan(1); Sun, Qibing(1); Li, Xuefeng(2)Source: Journal of Optics (United Kingdom) Volume: 16 Issue: 1 DOI: 10.1088/2040-8978/16/1/015206 Published: January 2014Abstract:Raman amplification based on stimulated Stokes Raman scattering (SSRS) and wavelength conversion based on coherent anti-Stokes Raman scattering (CARS) are theoretically investigated in silicon-on-sapphire (SOS) waveguides in the mid-infrared (IR) region. When the linear phase mismatch Δk is close to zero, the Stokes gain and conversion efficiency drop down quickly due to the effect of parametric gain suppression when the Stokes-pump input ratio is sufficiently large. The Stokes gain increases with the increase of Δk, whereas efficient wavelength conversion needs appropriate Δk under different pump intensities. The conversion efficiency at exact linear phase matching (Δk = 0) is smaller than that at optimal linear phase mismatch by a factor of about 28 dB when the pump intensity is 2 GW cm-2. ? 2014 IOP Publishing Ltd.Accession Number: 20140217174227 -
Record 396 of
Title:Effects of various room temperatures on terahertz radiation via optical parametric oscillator
Author(s):Huang, Nan(1); Liu, Hongjun(1); Sun, Qibing(1)Source: Optical Engineering Volume: 53 Issue: 6 DOI: 10.1117/1.OE.53.6.066112 Published: June 2014Abstract:A terahertz (THz)-wave parametric oscillator (TPO) pumped by a stable and single-longitudinal mode Q-switched Nd:YAG laser under various room temperatures is demonstrated. It is based on a cavity TPO architecture allowing stable single-resonance operation and low oscillation threshold. The output results, including the effects of the room temperature on this wavelength-agile TPO with a MgO:LiNbO3 crystal, indicate that the performance of TPO under the lower temperature is better. We obtain a widely tunable THz-wave source in the range 104 to 226 μmvia tuning the cavity flexibly under different room temperatures. The peak power of the THz wave reaches 220 mW at the wavelength of 146.2 μm when the room temperature is 20°C. The peak power of the THz wave decreases to 48 mW when the room temperature rises from 20°C to 25°C. ? 2014 Society of Photo-Optical Instrumentation Engineers.Accession Number: 20143418081681