Optical bistability based on surface plasmon coupled between a noble metal film and a metal grating involving Kerr materials

A phenomenon about optical bistability is successfully investigated in a layered structure consisting of a silver film with Kerr medium and a silver grating sandwiched between semi-infinite linear dielectrics.This type of structure can lead to the optical bistability phenomena occurring in reflection and transmission.There exists an optimal thickness of the metal grating that can cut off the effect of the near-field enhancement and may have the lowest effect on conversion from surface plasmon to light.This structure can realize the functions of the beam splitter and the polarization splitter and will be essential for future classical and quantum information processing.     

Design of a new kind of polarization splitter based on transformation optics

A scheme for a new two-dimensional polarization splitter is proposed based on the transformation optics. When a beam of arbitrary polarization illuminates upon the proposed polarization splitter, the TE (or TM) component is deflected whereas the TM (or TE) component propagates with no deflection. Moreover, the emerging propagation direction of the deflected component can be adjusted by rotating the polarization splitter. The simulation results demonstrated the feasibility and the flexibility of the polarization splitter. Design details and full-wave simulation results are provided.     

Polarization Sagnac interferometer with a reflective grating beam splitter

All-reflective interferometric gravitational-wave detector configurations with a diffraction grating as a power beam splitter have been proposed to reduce thermal lensing. We demonstrate the use of a diffraction grating as a polarization beam splitter in a zero-area polarization Sagnac interferometer.     

Switchable dual-wavelength Erbium-doped fiber ring laser with cascaded fiber Bragg gratings

We have experimentally shown wavelength mode switching in a dual-wavelength Erbium-doped single cavity fiber laser where the initial two wavelengths of 1 nm spacing are determined by the cascaded reflection type short-period fiber Bragg gratings having two different centre wavelengths of 1550.5 and 1551.5 nm. The lasing mode depends on the polarization in the ring cavity to migrate from one wavelength to another or operates in both modes in a polarization beam splitter output. To effectively control the polarization in the ring cavity, the polarization controllers were positioned before and after the polarization beam splitter. This method of wavelength switching provides a simple way of mode tuning in dual-wavelength fiber lasers.     

Isotope separation of32SF6 and12CF3I by a Q-switched CO2 laser

In the paper, polarization beam splitters are studied. Our theoretical study reveals that the coupling length and modulation period of a polarization beam splitter made from the depressed cladding fiber are shorter compared with that made from the matched fiber. Thus the former is characterized by a short interaction length. On the other hand, a polarization beam splitter made from the raised cladding fiber has a longer coupling length and a longer modulation period than those made from the matched fiber.     

Mutually pumped phase conjugate mirror using cross polarized photorefractive coupling

This paper presents a new proposal for a mutually pumped phase conjugate mirror (MPPCM) using cross polarization. In the cross polarized MPPCM, two light beams, whose polarizations are orthogonal to each other, incident on a photorefractive crystal, causing photorefractive interaction to generate phase conjugate waves with an orthogonal polarization to an incident beam. The use of Ar⁺ laser and BaTiO₃ crystal in an experiment for the cross polarized MPPCM found that diffraction efficiency for an extraordinary beam is about 20%. As opposed to a conventional parallel polarized MPPCM in which the use of a beam splitter is required to separate a diffraction beam, the cross polarized MPPCM can efficiently extract phase conjugate waves by means of a polarized beam splitter, demonstrating the advantage of substantially improved efficiency.     

Application of a fully vectorial beam propagation method

A new vectorial beam propagation method has successfully been applied to a passive polarization splitter and a passive polarization converter on InGaAsP/InP. The propagating fields are calculated and the power attenuation is evaluated. The calculated crosstalk values of the splitter are in good agreement with the realized best performance. A complete polarization conversion in the converter has also been simulated. This revised version was published online in November 2006 with corrections to the Cover Date.     

基于各向异性介质的偏振分束器

利用各向异性介质与各向同性介质构造了一维光子晶体,利用传输矩阵方法分析了它的能带结构,指出利用各向异性介质可以构造高消光比,全角度的偏振分束器件,并分析了它的理论基础.对影响偏振分束带宽的因素进行了分析.为进一步改进设计提出了方向.     

Polarization beam splitter with wide bandwidth in air-hole-based periodic dielectric waveguides

A polarization beam splitter with wide bandwidth and simple structure in air-hole-based periodic dielectric waveguides has been proposed and designed. Operation principle of the device is based on different directional coupling properties of beams in TE and TM polarizations in parallel periodic dielectric waveguides. Performances have been evaluated by a finite-difference time-domain simulation. Results show that the polarization beam splitter provides a wide bandwidth of 113 nm with both a high extinction ratio (higher than 21 dB) and a low insertion loss (less than 1.5 dB) for optical communication wavelengths at ∼1.55 μm. Moreover, the performances of the polarization beam splitter are insensitive to longitudinal alignment errors in the coupling region, which is desirable for device fabrication and practical application.     

Quantitative analysis of surface plasmon interaction with silver nanoparticles

The present insight into plasmon effects on the nanoscale seems sufficiently advanced to allow the development of surface-plasmon-polariton- (SPP-) based optical devices. Therefore quantitative information describing SPP phenomena is required. We investigate a SPP beam splitter constituted by silver nanoparticles on a silver thin film, fabricated by electron-beam lithography. We acquire quantitative information on the beam splitter performance by monitoring SPP leakage radiation, yielding SPP reflection, transmission, and scattering efficiencies.     

Polarization beam splitter based on photonic crystal self-collimation Mach-Zehnder interferometer

A polarization beam splitter based on a self-collimation Mach-Zehnder interferometer (SMZI) in a hole-type silicon photonic crystal was proposed and numerically demonstrated. Utilizing polarization dependence of the transmission spectra of the SMZI and polarization peak matching (PPM) method, the SMZI can work as a polarization beam splitter (PBS) by selecting appropriate path length difference in the structure. Because of its intrinsic operating principle, the PBS possesses high polarization extinction ratios (PERs). As its dimensions are only several operating wavelengths, the PBS may have practical applications in photonic integrated circuits.     

A reflective surface-relief two-layer grating for splitting beams with the polarization-selective property

A polarization-selective beam splitter is presented based on a reflective surface-relief two-layer grating with a metal slab. The grating is composed of two dielectric layers and a metal slab on the substrate. For TE polarization, efficiencies of 97.58% can be diffracted into the reflective −1st order. For TM polarization, two-port output of 47.55% and 47.11% can be split into the 0th order and the −1st order, respectively. Such a polarization-selective beam splitter can be fulfilled by one grating in reflection. The grating depths of two layers are optimized by using rigorous coupled-wave analysis with the given duty cycle of 0.6 and period of 1100 nm. The performance for different incident conditions is investigated when the incident wavelength and angle deviate from the central wavelength and the Bragg angle, respectively. For TM polarization, good uniformity can still be achieved within the given incident wavelength and angle regions. For TE polarization, the reflective polarization-selective beam splitter can have merits of wideband for different incident wavelengths.     

Ultra-compact polarization beam splitter based on photonic crystal waveguides

The authors design an ultra-compact all-PC-integrated polarization beam splitter which is only composed of three waveguides: one input waveguide and two output waveguides. The input waveguide can support both TM and TE modes, but one of the two output waveguides can only support TM modes while the other can only support TE modes. So an incident beam will be separated into two different polarization beams which emerge from different output waveguides. By the simulation of finite-difference time-domain method, we know that the polarization beam splitter really works the way as we predict.     

Polarization beam splitters based on a two-dimensional photonic crystal of negative refraction

A two-dimensional metallo-dielectric photonic crystal of negative refraction was designed for the application of polarization beam splitters. To match the refractive index of air, the effective refractive index of the designed photonic crystal is -1 for TE polarization and +1 for TM polarization. Two types of polarization beam splitter are presented.     

Broadband integrated polarization beam splitter with surface plasmon

A broadband integrated waveguide polarization beam splitter consisting of a metal nanoribbon and two dielectric waveguides is proposed and numerically investigated. This surface plasmon based device provides a unique approach for polarization sensitive manipulation of light in an integrated circuit and will be essential for future classical and quantum information processes.     

Polarizing beam splitter based on a double-layer subwavelength grating

A Si–ZnS double-layer subwavelength grating is theoretically used as a high-efficient polarizing beam splitter. To design this structure, the rigorous coupled-wave analysis (RCWA) is applied to study the reflectivity and transmissivity for the TE and TM polarization, respectively. Simulation results show that both the zero-order reflection for TE polarization and the zero-order transmission for TM polarization can exceed 90% in a wide tunable working incident angle range from 48° to 72°. Moreover, the proposed polarizing beam splitter has a working wavelength that is in the range of 1500–1600 nm.     

Archimedes 32,4,3,4结构光子晶体中与偏振无关的自准直分束器

通过等频图分析并结合时域有限差分法法模拟, 在Archimedes 3²,4,3,4结构排列的二维光子晶体中同一频率下同时实现了电磁波两种偏振态的自准直. 研究发现,在该结构光子晶体中引入缺陷,当线缺陷宽度改变时, TE和TM两种偏振态光束的分束效果将会随之变化.由此通过控制缺陷宽度,分别实现了两种偏振态光束的50% ∶50%分束以及90°大角度光折弯,分束和折弯的效率都较为理想,为未来设计基于光子晶体的新型光子学器件提供了一种新的思路.     

偏振模色散补偿中的偏振主态与分束器主轴的对准

光纤通信系统的比特率超过10Gb/s或更高时,偏振模色散引起的脉冲信号展宽成为主要障碍.分离光纤线路中的两个偏振模式对于提高偏振模色散补偿的精度和速度有重要意义.讨论了光纤线路中两偏振主态与补偿器中偏振分束器主轴的对准问题,给出了偏振分束器任何一个主轴上光强的表示并推导出相应的电功率信号表示式,建立了电功率与光信号两个模式之间的延迟时间以及偏振主态与分束器主轴相对角度的变化关系.初步实验表明,可以通过偏振控制器或可转动的光纤连接器实现偏振主态与偏振分束器的对准.     

一种基于双偏振分束器的量子秘密共享方案

提出一个基于双偏振分束器的单量子比特全光纤量子秘密共享方案, 该方案具有自动补偿光纤及光学器件的双折射效应和相位抖动的功能, 在干涉对比度测试和稳定性测试时, 该方案在5 km通信距离中, 获得的干涉对比度优于993%, 且可长时间保持稳定. 关键词： 量子秘密共享 偏振分束器 单光子干涉     

Design and fabrication of ultra-high precision thin-film polarizing beam splitter

An ultra-high precision thin-film polarizing beam splitter (PBS) has been designed and fabricated. Using Needle optimization technology, we design the thin-film polarizing beam splitter that is transparent for P polarization and reflective for S polarization with ultra-high precision at 64.8° angle of incidence and 632.8 ± 10 nm wavelength band. The experiments with the fabricated thin-film PBS demonstrate that both the reflectance of P polarization and transmittance of S polarization at 64.8° angle of incidence and 632.8 nm wavelength point are less than 0.02%, which is ultra-high for reported PBSs.