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A metric is proposed that allows reliable prediction of the maximum bistatic angle for which the monostatic-to-bistatic equivalence theorem (MBET) can be used. Currently, the theorem leaves the term "sufficiently smooth" undefined, making selection of the maximum angle somewhat subjective. The proposed metric provides a quantitative evaluation of complexity/smoothness, and relates this to an angle limit based on an empirically derived statistical error profile. That is, the metric allows prediction of the maximum bistatic angle for which the MBET provides less than a 1.5 dB error at a confidence level of 95%. Although the metric is presently only demonstrated for two-dimensional (2D) objects at a single polarization and error value, sufficient experiments following the same process can easily extend the method to three-dimensional objects, arbitrary polarizations, and alternate error tolerances. Such a capability allows for optimization of either monostatic collections used for prediction of bistatic data sets, or bistatic computations interpolated to monostatic results.

Addresses the land-use classification capabilities of fully polarimetric synthetic aperture radar (SAR) versus dual-polarization and single-polarization SAR for P-, L-, and C-band frequencies. A variety of polarization combinations are investigated for application to crop and tree age classification. Based on the complex Wishart distribution for the covariance matrix, maximum likelihood classifiers for all polarization combinations are used to assess quantitative classification accuracy. Thus, this allows optimally selecting the frequency and the combination of polarizations for various applications.

Cutoff wavelengths are calculated for the fundamental modes of W-tunneling optical fibers. The results are compared with the existing experiments and other calculations. They are in close agreement with one another. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 292–296, 2000.

We demonstrate single-polarization operation of a distributed Fabry-Perot multiwavelength fiber laser by adding an external cavity with polarization-dependent feedback. We show that the laser lines retain single-frequency operation with the additional benefit of reduced linewidth. The laser source covers the full C-band with 100-GHz channel spacing.

We find that single spin asymmetries in NRQCD are non-vanishing in general. They are proportional to the imaginary parts of some non-perturbative matrix elements. With statistics of about 10^6 identified J/psi's, or 10^5 identified chi_2, it is possible to measure these imaginary parts even if they are an order of magnitude smaller than the real parts. Such statistics are quite reasonable at polarised HERA N and other future experiments., Comment: Plain LaTeX with one figure (ps)

We present experimental results on one-dimensional (1-D) spatial solitons in AlGaAs waveguides. Three distinct types of spatial solitons have been observed: namely the fundamental soliton, the Manakov soliton, and the vector soliton. The fundamental soliton is the simplest form of 1-D soliton which consists of a single polarization. The properties of waveguiding and ‘robustness’ are experimentally studied. Vector solitons which result from the complex interplay between the two orthogonally polarized beams due to self-phase modulation, cross-phase modulation, and four-wave mixing effects are studied. The complex beam dynamics and polarization behaviour of the vector solitons are experimentally studied. Manakov solitons which are a special case of the vector soliton exist when the ratio between the self-to-cross-phase modulation is one and the four-wave mixing effects becomes zero are demonstrated experimentally and the basic properties discussed. Finally, some soliton interactions such as trapping and dragging are reported and possible applications of soliton interactions are discussed.

In this letter, a novel design for a photonic crystal fiber coupler with single-polarization single-mode (SPSM) functionality is proposed and investigated using a vector plane-wave expansion method and a vector finite-element method. We study the changes in the coupling lengths between the two orthogonal polarizations and the width of the SPSM coupling region with respect to the air-hole parameters. We demonstrate that the SPSM coupling range can be more than 200 nm wide for a variety of air-hole parameters and show that the position and width of the SPSM coupling region can be tailored via the diameters of the large inner air holes and the small cladding air holes

We experimentally examine the performance of a single-polarization 42.7-Gb/s return-to-zero differential quadrature phase-shift keying optical signal. We evaluate the penalties arising from chromatic dispersion, polarization-mode dispersion, narrowband optical filtering, and nonlinear transmission over standard single-mode fiber.

Single-polarization 160-Gb/s-based wavelength-division-multiplexing (WDM) field transmission has been successfully demonstrated. By using a return-to-zero differential phase-shift-keying modulation format and a simple polarization-mode dispersion compensator, we have successfully demonstrated single-polarization 8/spl times/160 Gb/s WDM transmission without the polarization demultiplexing.

Many applications require laser emission with stable single polarization. While stable transverse-electric (TE) emission is favored by several mechanisms and, consequently, is relatively easy to obtain, achieving stable transverse-magnetic (TM) emission is more difficult. This letter proposes a method for suppressing the TE polarization by using a multiquantum-barrier. In our experiments, the multiquantum-barrier structure was inserted into the p-type cladding of tensile-strained GaInP-AlGaInP quantum-well lasers emitting at wavelengths shorter than 630 nm. As a result, the TE emission was suppressed over a wide range of injection levels, operating temperatures, and device lengths, proving that the method is effective for achieving stable TM emission.

A novel dual polarization differential quadrature phase shift keying (DP-DQPSK) system is proposed, whose receiver is the same as the single polarization DQPSK system, while it does not need polarization de-multiplexing like the conventional polarization division multiplexing QPSK (PDM-QPSK). Polarization mode dispersion (PMD) is mainly considered and PMD compensation for the DP-DQPSK system is studied. As the feedback signal for PMDcompensation, the degree of polarization of the signals is discussed in detail. The results show that PMD tolerance can be improved by 89 ps within 1 dB optical signal noise ratio penalty after PMD compensation for the DP-DQPSK system.

We propose a novel scheme of direct-detection optical OFDM system based on block-wise signal-phase-switching (SPS). Experimental demonstration of 48.8-Gb/s SPS-DDO-OFDM signal transmission over 80-km SSMF was achieved with single polarization and photo-detector.

Three dimensional waveguides within the bulk of diamond are manufactured using ultrafast laser fabrication. High intensities within the focal volume of the laser cause breakdown of the diamond into a graphitic phase leading to a stress induced refractive index change in neighboring regions. Type II waveguiding is thus enabled between two adjacent graphitic tracks, but supporting just a single polarization state. We show that adaptive aberration correction during the laser processing allows the controlled fabrication of more complex structures beneath the surface of the diamond which can be used for 3D waveguide splitters and Type III waveguides which support both polarizations.

Materials with a periodic structure have photonic bandgaps (PBGs), in which light can not be guided within certain wavelength ranges; thus light can be confined within a low-index region by the bandgap effect. In this paper, rectangular-shaped hollow waveguides having waveguide-walls (claddings) using the PBG have been discussed. The design principle for HE modes of hollow-core rectangular PBG waveguides with a Bragg cladding consisting of alternating high- and low-index layers, based on a 1D periodic multilayer approximation for the Bragg cladding, is established and then a novel single-polarization hollow-core square PBG waveguide using the bandgap difference between two polarized waves is proposed. Our results demonstrated that a single-polarization guiding can be achieved by using the square Bragg cladding structure with different layer thickness ratios in the mutually orthogonal directions and the transmission loss of the guided mode in a designed hollow-core square PBG waveguide is numerically estimated to be 0.04 dB/cm.

We propose the temperature-insensitive bending sensor based on a hole-assisted single polarization fiber (SPF). Without fiber grating structures, the SPF-based sensing probe can provide the sensing technique to measure the bending change. If bending is applied to the SPF, two cutoff wavelengths are shifted to shorter wavelengths and the transmission power is diminished because the structural deformation of the SPF induced by bending changes birefringence depending on principle axes of the SPF. However, the applied temperature variation has no effect on the birefringence change severely and two cutoff wavelengths are not shifted by changing temperature. Therefore, the proposed SPF-based sensing probe with temperature insensitivity can measure the bending change effectively.

If two independent signals are communicated using orthogonal polarizations, the communication throughput is doubled compared to a single polarization. Polarization reuse superimposes two independent signals in the same bandwidth and requires design attention to obtain adequate isolation between the signals to avoid cochannel interference. Polarization reuse is limited to doubling the communication throughput because any polarization has only one orthogonal polarization. A new technique uses multiple non-orthogonal polarizations and signal processing techniques to separate and combine multiple signal components and can more than double the communication throughput.

A Sagnac loop filter with two pieces of high birefringence fiber having equal lengths, and spliced together at a fixed angle of 30o displacement between the two principle axes, is proposed in this letter. Gain equalization of erbium-doped fiber amplifiers (EDFAs) is implemented by tuning only the polarization controller in the loop filter. Experimental result shows that there remains a deviation of \pm 1 dB in the region of the flattened profile with the useful bandwidth of about 23 nm, thereby demonstrating the effectiveness of the method. An effective mathematical model and mechanism is also given for further explanation. Published version

A kind of single-polarization and single-mode totally internal reflection photonic crystal fiber (SPSM TIR-PCF) is proposed in this paper. It is a PCF structure with elliptical air holes in the cladding and four large holes in the first ring. A full-vector plane wave expansion method is employed to analyze this PCF structure. The numerical results show that this PCF structure can realize an ultra-broad SPSM bandwidth of 540 nm with a confinement loss less than 0.1 dB km−1, the broadest bandwidth to the best of our knowledge. Moreover, the structure that we proposed can realize a high nonlinear coefficient.

The Electronic Multi-beam Radio Astronomy Concept (EMBRACE) is the first full-scale prototype of an SKA phased array station. This single polarization demonstrator operates between 500 and 1500 MHz. The station that is currently being built at the site of the Westerbork Synthesis Radio Telescope, will ultimately consist of 144 tiles with 72 single polarization Vivaldi antennas each, giving a total of ∼ 104 elements. The station is equipped with a LOFAR station backend with 192 input channels, which can be exploited for real-time digital beam forming in 248 frequency channels of 195 kHz (∼ 48 MHz total bandwidth) and correlation in a single 195 kHz frequency channel. In this paper we present the results from a number of system validation measurements and the first fringes on an astronomical source, the sun. These initial measurements indicate a system temperature between 103 K and 117 K. These results corroborate the feasibility and applicability of phased array technology at frequencies below 1500 MHz. They also provide valuable insights for the aperture array verification program, the next step in aperture array development towards the SKA.

We propose the temperature-insensitive bending sensor based on a hole-assisted single polarization fiber (SPF). Without fiber grating structures, the SPF-based sensing probe can provide the sensing technique to measure the bending change. If bending is applied to the SPF, two cutoff wavelengths are shifted to shorter wavelengths and the transmission power is diminished because the structural deformation of the SPF induced by bending changes birefringence depending on principle axes of the SPF. However, the applied temperature variation has no effect on the birefringence change severely and two cutoff wavelengths are not shifted by changing temperature. Therefore, the proposed SPF-based sensing probe with temperature insensitivity can measure the bending change effectively.

Multiple Aperture Transform Chip Heterodyne (MATCH) spectrometers have been developed for targeted remote sensing applications in harsh environments. These waveguide-based Fourier Transform Spectrometers (FTS) offer significant improvements in resource efficiency over monolithic glass implementations, but are relatively limited in terms of input coupling efficiency and fill factor of the input facet. Integrated optics spectrometers have significant resource advantages for space applications. Monolithic Spatial Heterodyne Spectrometers are insensitive to vibration and do not require frequent calibration. In addition, Fourier Transform Spectrometers are known to provide significant performance advantages for emission spectroscopy. Ongoing work will improve the MATCH spectrometer input coupling efficiency from free space. This paper discusses the signal to noise improvements expected by incorporation of surface gratings, or back-thinning and stacking of slabs. We show that the use of surface gratings can increase the throughput over coupling to bare waveguides alone (in a single polarization), and provide close to 100% fill factor, albeit with limited field. Étendue improvements associated with stacked slabs are limited only by the sensing area available, but the fill factor of the input facet is limited to ∼10%. The impact of these improvements is assessed in the context of two space-based applications: 1) Atmospheric remote sensing in the context of Spatial Heterodyne Observations of Water (solar occultation absorption spectroscopy) near 1.3 μm and 2) Point emission spectroscopy (LIBS/Raman/fluorescence) for mineral identification on a planetary rover. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE)., Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS and Nanodevices X, January 24-25, 2011, San Francisco, CA, USA, Series: Proceedings of SPIE; no. 7928

PMD mitigation in 2×10-Gb/s RZ-OOK PDM systems is demonstrated through a single all-optical-regenerator with polarization-diversified loop configuration. 3.0-dB eye-diagram-based SNR improvement is achieved in the presence of 6.3-ps DGD for RZ signals with 18-ps pulsewidth.

Climatological and hydrological investigations in mountainous regions frequently require delineation of the areas covered by snow and glacial ice. Active microwave sensors can discriminate snow and glacier from other targets, are effective under all weather conditions, and have a spatial resolution compatible with the topographic variation in alpine regions. Using data acquired with the NASA AIRSAR, which operates at three frequencies and four combinations of polarization, we examine the usage of synthetic aperture radar (SAR) to map snow- and glacier-covered areas. In order to assess the available SARs that operate from satellites, we analyze single-frequency, single-polarization data, and we compare our results with images from the Landsat Thematic Mapper obtained under clear conditions only a few days after the SAR flight. Single polarization, C-band (5.3 GHz) SAR data can discriminate between areas covered by wet snow from those that are ice-free, but do not easily separate glacier ice from snow and rock. L-band SAR (1.25 GHz) data cannot discriminate between snow and glacier ice. The accuracy (74%) of SAR is high enough to justify its use as the data source in areas that are too cloud-covered to obtain reliable data from the thematic mapper.

We were experimental demonstrated the transmission characteristic of Sagnac loop mirror based on single polarization fiber (SPF). The interference fringe of Sagnac loop mirror was not revealed at specified wavelength range, because of SPF with cutoff polarization states. The sensitivities of Sagnac loop mirror based on SPF applied strain and temperature was measured to be 0.72 nm/m and 2.24 nm/°C, respectively.

It is presented a single-polarization operation of a Hybrid Photonic Crystal Fiber with at least 200 nm bandwidth. Experimental results demonstrate polarization dependent loss as high as 23 dB on the photonic bandgap edge. Near field images are also presented.

Several strategies to achieve 100 Gb/s throughput for single polarization DD-OFDM are considered. Based on state-of-the-art in converter technology, using higher order modulation formats a concept aiming at high sensitivity is proposed.

The feasibility of transmitting 0.87 Tbit/s dual polarization D8PSK-OTDM over 110 km is, for the first time, demonstrated along with 0.44 Tbit/s single polarization D8PSK-OTDM over 220 km in conventional 55-km span SMF+DCF link.

In this paper, 40 Gbaud transmission of single polarization (SP) and Polarization-Multiplexed (PM), RZ-DQPSK and RZ-D8PSK signals is analyzed numerically. The impact of nonlinear crosstalk arising from the presence of neighbouring intensity-modulated channels is analyzed in terms of required OSNR for the BER of 10-3versus launch power. QC 20120607

The single polarization observables Σ , P and T are presented for the reaction 3 He( γ , π + ) 3 H at various kinematics. The process is described in a recently developed nonlocal coupled-channel framework that employs three-body Faddeev amplitudes and incorporates two-step processes such as 3 He( γ , π 0 ) 3 He( π 0 , π + ) 3 H. Enhancement effects of the contributions from small components of the 3 He wave function as well as from the Δ-resonance E2 transition to the polarization observables have been found.

The analytic theory governing the complete scattering response of two-dimensional (2-D) microring resonator arrays is developed, The method is applicable to arbitrary interconnections of general four-port, single polarization nodes. An 8/spl times/8 cross-grid array of vertically coupled glass microring resonators is fabricated for test purposes.

A rigorous theoretical analysis has been presented of the stress birefringence B(s) and the polarization dispersion D(s) in single-polarization fibers. Both B(s) and D(s) vary considerably in dependence on normalized frequency nu, and the nu-value dependence of B(s) and D(s) is strongly affected by the anisotropic stress distribution in the fiber. It is shown that the experimental results agree well with the calculated ones.

A vectorial finite element method is adopted to investigate this novel single-mode single-polarization (SPSM) photonic crystal fiber coupler which has asymmetric dual-core and two lines of enlarged air holes. we demonstrate that the SPSM region of the designed fiber can be more than 250nm wide for a set of optimized air-hole parameters and show that the width of the SPSM region could change slightly by little adjustment of the large inner air holes. The coupling length between the odd and even x-polarization modes are also investigated through fine-tuning the large and small air-hole diameters.

We study the effects of bending on single polarization fiber performance through the use of finite element method in conjunction with the perfectly matched layer (PML) in cylindrical geometry. The cylindrical PML used in this paper allows us to calculate the loss associated with each polarization mode at a given wavelength, specified bending diameter, and specific orientation. We identified a series of bending characteristics of the single polarization fiber by choosing different bending diameters and different orientations. We also conducted experiments to study some aspects of the bending. Good qualitative agreement between numerical and experimental results is found, which helps to understand fiber deployment conditions and can potentially facilitate new design efforts.

A novel integrated TM-pass waveguide polarizer with a subwavelength-wide slot is introduced and theoretically analyzed. With a proper design of the slot, the waveguide can be used as a single polarization waveguide to guide only TM polarization modes of the light signal. With 26 microm length of this TM-pass polarizer, our computer simulations predict the insertion loss of 0.54 dB for the TM polarization mode with the extinction ratio of 20.3 dB at the wavelength of 1.55 microm.

Synthetic Aperture Radar (SAR) sensors offer the coverage rate and all-weather capability necessary for wide-area surveillance and can provide very useful information for the detection and characterization of surface targets. Conventional SARs operate with a single polarization channel, while recent and future spaceborne SARs (Envisat ASAR, Radarsar-2) will offer the possibility to use multiple polarization channels, which will enable better detection and characterization of man-made objects. Standard target detection approaches on SAR images consist in the application of a Cell Averaging or 2-parameters CFAR detector and usually produce a large number of false alarms. This large number of false alarms prohibits their manual rejection. However, over the past ten years a number of algorithms have been proposed to extract information from a polarimetric SAR scattering matrix in order to enhance and/or characterize man-made objects. Target decomposition algorithms, such as Cameron’s coherent target decomposition (CTD) and the Odd-Even basis decomposition, provide information for detecting ships and reducing false alarms. On the other hand, information derived from spectral analysis, such as the subaperture coherence, enhance the ship’s signature and allow a better discrimination of the desired target. The evidential fusion of such information can lead to the automatic rejection of the false alarms generated by the CFAR detector. In addition, the aforementioned information can lead to a better characterization of detected targets. This paper presents an approach, as well as results, for automatic target detection using the evidential fusion of polarimetric features and the spectral analysis technique. Preliminary results for ship characterization using polarimetric information are also presented. This research is motivated by airborne/spaceborne surveillance applications such as land and coastal surveillance missions using SAR/PolSAR imagery.

A novel and simplest polarization microscope by single polarization modulation method to visualize cytoskeletal structure in bio-cells have been developed. The polarization microscope visualizes cytoskeletal structure based on birefringence characteristics of cells. In the polarization microscope, a series of intensity images according to single modulation of rotating linear polarizer were obtained to visualize cytoskeletal structure. Phase retardation and principal axis orientation were calculated by analytic data processing from the acquired intensity images. Phase retardation and principal axis orientation of breast cancer cells, MCF 7 and MDA MB 231 were measured and visualized as their birefringence characteristics by the polarization microscope. Phase retardation sensitivity of the polarization microscope system also was measured in this paper.

We establish rigorous necessary analytical conditions for the existence of single-polarization single-mode (SPSM) bandwidths in index-guided microstructured waveguides (such as photonic-crystal fibers). These conditions allow us to categorize designs for SPSM waveguides into four strategies, at least one of which seems previously unexplored. Conversely, we obtain rigorous sufficient conditions for the existence of two cutoff-free index-guided modes in a wide variety of microstructured dielectric waveguides with arbitrary periodic claddings, based on the existence of a degenerate fundamental mode of the cladding (a degenerate light line). We show how such a degenerate light line, in turn, follows from the symmetry of the cladding.

We demonstrated experimentally a stable single-frequency single-polarization fiber ring laser at 1053 nm. The measured linewidth is less than 10 kHz.

HJ-1C will be launched at the end of 2008, it is a component of HJ satellites which are developed in China. HJ-1C SAR has a frequency of S-band (3.2 GHz), VV single polarization, and incident angle range from 25deg-47deg. Soil moisture retrieval using L- and C-band radar has been widely studied, but little attention was paid to S-band data. For the application of HJ-1C SAR, in this paper, the available data of S-band radar data by PALS (Passive and Active L- and S-band sensor) from SGP99 and SMEX02 experiments was used to study the potential of soil moisture change retrieval using S-band single polarization radar.

We propose a new fiber structure using both stress rods and air holes for making wide band single polarization fibers as well as polarization maintaining fibers, and illustrate the results through finite element modeling.

New Giant Meterwave Radio Telescope (GMRT) observations of the five‐component pulsar B1857–26 provide insight into its pulse‐sequence modulation phenomena. The outer conal components exhibit a 7.4‐rotation‐period longitude‐stationary modulation. Several lines of evidence indicate a carousel circulation time of about 147 stellar rotations, characteristic of a pattern with 20 beamlets. We also find that the pulsar nulls some 20% of the time, usually for only a single pulse, and that these nulls show no discernible pattern. Finally, the polarization‐angle traverse raises interesting issues: if most of its emission is comprised of a single polarization mode, the full traverse exceeds 180°.

Numerical simulations indicate possibility of long-haul transmission with 1.0 bit/sec-Hz spectral efficiency per polarization, based on intensity modulated principles with low complexity equalization at the receiver.

The generation of high-power and stable ultra-short pulses from a passively mode-locked purely normal dispersion fiber laser is reported using the unique combination of a photonic crystal fiber featuring single-polarization, single-mode, and low nonlinearity with a high modulation depth semiconductor saturable absorber mirror. The environmentally-stable, self-starting fiber laser generates 1.6 W of average power at a repetition rate of 63 MHz, corresponding to a pulse energy of 25 nJ. The emitted pulses are positively chirped with a pulse duration of 3.7 ps. They are compressible down to a near transform-limited duration of 750 fs. Numerical simulations are in good agreement with the experimental results.

A set of coupled power equations derived from that of amplitude equations for single-polarization (SMSP) optical fibers has been presented. Our results show that the power coupling coefficients are related not only to the effect of the birefringence of SMSP fibers, but also to the leaky mode loss.

In French Guiana, the constant migration of large mud banks resulting from the Amazon River's sedimentary discharge has a negative impact on the local economy. Two radar images from the new ASAR/Envisat sensor have been analysed and compared to one ASTER image to assess their potential for mud bank monitoring. Bathymetric data were also recorded at times close to those of the satellite acquisitions, enabling a comparative study of the mud bank morphology and bathymetry and satellite information. The emerged parts of the mud banks, whether consolidated/solid (slikke or mudflats, mud bars, etc.) or fluid mud are easily detectable on the ASAR images. However, the results show that mud bank covered by a shallow layer of water (a few tens of centimetres) is not detectable on ASAR images. For deeper waters the ASAR signal is independent of water depth. ASAR's multipolarized images provide little more information than that obtained from older sensors having only a single polarization (ERS-1/2 and RADARS...

The potential of Advanced Synthetic Aperture Radar (ASAR) for the retrieval of surface soil moisture over bare soils was evaluated for several ASAR acquisition configurations: (1) one date/single channel (one incidence and one polarization); (2) one date/two channels (one incidence and two polarizations); (3) two dates/two channels (two incidences and one polarization); and (4) two dates/four channels (two incidences and two polarizations). The retrieval of soil moisture from backscattering measurements is discussed, using empirical inversion approaches. When compared with the results obtained with a single polarization (HH or HV), the use of two polarizations (HH and HV) does not enable a significant improvement in estimating soil moisture. For the best estimates of soil moisture, ASAR data should be acquired at both low and high incidence angles. ASAR proves to be a good remote sensing tool for measuring surface soil moisture, with accuracy for the retrieved soil moisture that can reach 3.5% (RMSE).