2012

• Record 337 of
  
  Title:Analyses of mode field propagation properties in fuse-tapered fibers
  
  Author(s):Zhou, Liang(1); Duan, Kailiang(1)
  Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering  Volume: 41  Issue: 3  DOI:   Published: March 2012  
  Abstract:Applications such as near-field optical-microscope and high power fiber coupler require more precise understanding of light field in fuse-tapered fiber. To study propagation properties of the fuse-tapered fiber, field distributions were simulated by finite-difference time-domain method (FDTD), assuming that the incident beam was fundamental mode. Theoretical model of fuse-tapered fiber used in the simulation was based on a tapering function which was close to the real shape of fuse-tapered fiber. Mode field radius and transverse field distribution of the fuse-tapered fiber in the fundamental mode Gaussian approximation were compared with the simulation results. Finally, the influences of the initial melting length and extension length on the transmission efficiency were analyzed. The results show that field distribution in the fuse-tapered fiber is asymmetric though the shape of fuse-tapered fiber is symmetric. When a fundamental mode field propagates through a fuse-tapered fiber, the light field propagates not only as fundamental mode which is corresponding to the core diameter of the fuse-tapered fiber. The fundamental mode Gaussian approximation may introduce considerable errors to the calculation of field distribution in fuse-tapered fiber. When fuse-tapered fiber is of single cone type or double cone type, the influences of their shapes are different. To get higher transmission efficiency, initial melting length and extension length should be optimized according to the specific applications.
  Accession Number: 20121915007921
• Record 338 of
  
  Title:Free-space propagation of guided optical vortices excited in an annular core fiber
  
  Author(s):Yan, Hongwei(1); Zhang, Entao(1); Zhao, Baoyin(1); Duan, Kailiang(1)
  Source: Optics Express  Volume: 20  Issue: 16  DOI: 10.1364/OE.20.017904  Published: July 30, 2012  
  Abstract:The analytical expression for the propagation of guided optical vortices through free space is derived and used to study the dynamic evolution of guided optical vortices after passing through the free space, and the dependence of guided optical vortices on the control parameters where the effect of propagation distance is stressed. It is shown that the motion, pair creation and annihilation of guided optical vortices may take place. In particular, the creation and annihilation of a pair of guided optical vortices do not take place by varying fiber length. © 2012 Optical Society of America.
  Accession Number: 20123215326098
• Record 339 of
  
  Title:Optical bistability based on an analog of electromagnetically induced transparency in plasmonic waveguide-coupled resonators
  
  Author(s):Cui, Yudong(1); Zeng, Chao(1)
  Source: Applied Optics  Volume: 51  Issue: 31  DOI: 10.1364/AO.51.007482  Published: November 1, 2012  
  Abstract:We have investigated numerically an optical bistability effect based on an analog of electromagnetically induced transparency (EIT) in a nanoscale plasmonic waveguide-coupled resonator system. The system consists of a metal-insulator-metal waveguide side-coupled with a slot cavity and a nanodisk cavity containing Kerr nonlinear material. By finite-difference time-domain simulations, the EIT-like spectral peak has a redshift with an increase of the dielectric constant of the nanodisk cavity. More importantly, we have achieved an optical bistability with threshold intensity about three times lower than that of recent literature [Appl. Opt. 50, 5287 (2011)]. The results show that our plasmonic structure can find more excellent application in highly integrated optical circuits, especially all-optical switching. © 2012 Optical Society of America.
  Accession Number: 20124515652917
• Record 340 of
  
  Title:Virtual source for an Airy beam
  
  Author(s):Yan, Shaohui(1); Yao, Baoli(1); Lei, Ming(1); Dan, Dan(1); Yang, Yanlong(1); Gao, Peng(1)
  Source: Optics Letters  Volume: 37  Issue: 22  DOI: 10.1364/OL.37.004774  Published: November 15, 2012  
  Abstract:We identify a virtual source for generating an Airy wave. A spectral integral expression is derived to describe the Airy wave, which, in the paraxial limit, yields the freely accelerating, nondiffracting, and finite energy Airy beam. From the spectral representation of the Airy wave, the first two orders of nonparaxial corrections to the paraxial Airy beam are determined. Also, aconnection between the obtained Airy wave and the well-known complex source point spherical wave is given. © 2012 Optical Society of America.
  Accession Number: 20124715698563
• Record 341 of
  
  Title:Phases in a general chaotic three-coupled-laser array
  
  Author(s):Zhou, Liang(1); Duan, Kai-Liang(1)
  Source: Chinese Physics Letters  Volume: 29  Issue: 4  DOI: 10.1088/0256-307X/29/4/044201  Published: April 2012  
  Abstract:Phases in a general chaotic three-coupled-laser array are numerically investigated. Phase attractors are firstly found to exist within corresponding basins of attraction on the projection plane of phase differences of the three-coupled-laser array. Whether the chaos appears or not is related not only to the coupling strength but also to the initial phase differences. For a large coupling strength new phase attractors can occur. With the increase of coupling strength, the three-coupled-laser array has a great chance of resulting in a quiescent to chaotic state. Based on these results, we present the method to reach phase-locking when the coupling strength is strong. © 2012 Chinese Physical Society and IOP Publishing Ltd.
  Accession Number: 20220711662441
• Record 342 of
  
  Title:Theoretical analysis of output performance of GG-IAG fiber laser by multipoint distributed side pump
  
  Author(s):Zhu, Yonggang(1); Duan, Kailiang(1); Shao, Hongmin(1); Zhao, Baoyin(1); Zhang, Entao(1); Zhao, Wei(1)
  Source: Optics Communications  Volume: 285  Issue: 24  DOI: 10.1016/j.optcom.2012.08.019  Published: November 1, 2012  
  Abstract:Based on a steady-state rate equations (REs) and heat dissipation model considering both convective and radiative heat transfer, the output performance and temperature distribution of Yb3 doped gain guided and index antiguided (GG-IAG) fiber lasers by multipoint distributed pumping are analyzed by numerically solving REs. The results show that high output power and even temperature distribution can be obtained by increasing pump points and lowering the losses at the points; multipoint side pumping is an optimal method to obtain compact high power GG-IAG fiber lasers. The numerical analysis provides some insights for the construction of high power GG-IAG fiber lasers. © 2012 Elsevier B.V. All rights reserved.
  Accession Number: 20124315591127
• Record 343 of
  
  Title:Theoretical prediction of three-dimensional shifting of a spherical focal spot in a 4Pi focusing system
  
  Author(s):Li, Ze(1,2); Yan, Shaohui(1); Yao, Baoli(1); Lei, Ming(1); Ma, Baiheng(1); Gao, Peng(1); Dan, Dan(1); Rupp, Romano(3)
  Source: Journal of Optics  Volume: 14  Issue: 5  DOI: 10.1088/2040-8978/14/5/055706  Published: May 2012  
  Abstract:A spherical focal spot can be generated by focusing radially polarized laser beams in a 4Pi focusing system, which will result in an increase in axial resolution in microscopy or higher axial trapping efficiency. We demonstrate the possibility of continuous shifting of the spherical focal spot along the prescribed trajectory in three-dimensional space by suitably modulating the phase of the input fields at the pupil planes of the microscope objective lenses. This may provide an alternative to moving trapped particles or scanning a specimen without moving either laser beams or the stage. © 2012 IOP Publishing Ltd.
  Accession Number: 20121915012818
• Record 344 of
  
  Title:Terahertz absorption spectra of benzene-1,2-diol, benzene-1,3-diol and benzene-1,4-diol
  
  Author(s):Zheng, Zhuan-Ping(1); Fan, Wen-Hui(1); Yan, Hui(1)
  Source: Chemical Physics Letters  Volume: 525-526  Issue:   DOI: 10.1016/j.cplett.2011.12.062  Published: February 16, 2012  
  Abstract:The terahertz spectra (8-128 cm-1) of three structural isomers have been measured using terahertz time-domain spectroscopy at room temperature. Substantial differences among these THz spectra have been found and implied that THz-TDS is an excellent tool to identify isomers. Numerical calculation based on solid-state density functional theory has been carried out and assigned the observed THz features theoretically. Good agreement between the calculated and experimentally measured spectra for benzene-1,2-diol and benzene-1,3-diol has been achieved. According to the calculated results, it is found that the measured THz spectra of these two isomers mainly originate from intermolecular vibrations. © 2012 Elsevier B.V. All rights reserved.
  Accession Number: 20120714763420
• Record 345 of
  
  Title:Autofocusing of digital holographic microscopy based on off-axis illuminations
  
  Author(s):Gao, Peng(1); Yao, Baoli(1); Min, Junwei(1); Guo, Rongli(1); Ma, Baiheng(1); Zheng, Juanjuan(1); Lei, Ming(1); Yan, Shaohui(1); Dan, Dan(1); Ye, Tong(1)
  Source: Optics Letters  Volume: 37  Issue: 17  DOI: 10.1364/OL.37.003630  Published: September 1, 2012  
  Abstract:An auto-focusing method for digital holographic microscopy has been proposed by employing two off-axis illumination beams. When specimens are illuminated by two plane waves in different directions, it is found that the farther the reconstruction plane is from the image plane, the wider the two reconstructed images are separated from each other. Thus, the image plane can be determinated by finding the minimum of the variation between the two reconstructed object waves on both the amplitude and phase distributions. The feasibility of the proposed method is demonstrated by the corresponding simulation and experiment. © 2012 Optical Society of America.
  Accession Number: 20123715419559
• Record 346 of
  
  Title:Observations of three types of sidebands in a passively mode-locked soliton fiber laser
  
  Author(s):Han, D.D.(1); Yun, L.(1)
  Source: Laser Physics  Volume: 22  Issue: 12  DOI: 10.1134/S1054660X12120092  Published: December 2012  
  Abstract:We have experimentally observed three types of sidebands in a passively mode-locked soliton fiber laser with large anomalous dispersion for the first time to our best knowledge. By appropriately adjusting the polarization state of laser cavity, the conventional peak sidebands, peak-dip sidebands, and dip sidebands appear in the soliton spectra, respectively. The peak-dip and dip sidebands exhibit distinct characteristics from the conventional peak sidebands. The formation mechanism of the new type sidebands can be attributed to the periodic power variation. This work could help to a deeper insight of the spectrum shaping mechanism of conventional solitons. © 2012 Pleiades Publishing, Ltd.
  Accession Number: 20130916047952
• Record 347 of
  
  Title:Observation of dual-wavelength dissipative solitons in a figure-eight erbium-doped fiber laser
  
  Author(s):Yun, Ling(1); Liu, Xueming(1); Mao, Dong(1)
  Source: Optics Express  Volume: 20  Issue: 19  DOI: 10.1364/OE.20.020992  Published: September 10, 2012  
  Abstract:We report on the generation of dual-wavelength dissipative solitons (DSs) in a passively mode-locked figure-eight fiber laser operating in the net-normal dispersion regime. DSs with central wavelengths of 1572 and 1587 nm can be achieved simultaneously or respectively. The dualwavelength DSs, traveling at different round-trip time, exhibit doublerectangular spectral profile. The intensities of two mode-locked spectra decrease or increase simultaneously after passing through a polarization beam splitter, indicating that the dual-wavelength DSs almost share the same polarization state. Experimental results demonstrated that dualwavelength mode locking strongly depends on birefringence-induced filtering effect. © 2012 Optical Society of America.
  Accession Number: 20123815452193
• Record 348 of
  
  Title:Generation of broadband cascaded four-wave mixing products in silicon-on-insulator waveguide
  
  Author(s):Wen, Jin(1); Liu, Hongjun(1); Huang, Nan(1); Sun, Qibing(1); Zhao, Wei(1)
  Source: Optical Engineering  Volume: 51  Issue: 2  DOI: 10.1117/1.OE.51.2.024601  Published: February 2012  
  Abstract:We present a new method to generate broadband cascaded four-wave mixing (FWM) products in the silicon-on-insulator (SOI) waveguide. A simulation model of the nonlinear Schrödinger equation is used to describe the cascaded FWM in the SOI waveguide, which consists of launching two strong pump waves near the zero-dispersion wavelength of the very short (just a few millimeters) SOI waveguide. The numerical results based on the split step Fourier method have demonstrated that the output cascaded FWM products represent bandwidth of more than 1000 nm (range from C-band to IR-band). We also analyze the remarkable influences of parameters of the waveguide length, the pump power, and the dispersion slope on the cascaded FWM products in the SOI waveguide. © 2012 Society of Photo-Optical Instrumentation Engineers (SPIE).
  Accession Number: 20140317194203