Photonic circuits for generating modal, spectral, and polarization entanglement

We consider the design of photonic circuits that make use of Ti:LiNbO$_{3}$ diffused channel waveguides for generating photons with various combinations of modal, spectral, and polarization entanglement. Down-converted photon pairs are generated via spontaneous optical parametric down-conversion (SPDC) in a two-mode waveguide. We study a class of photonic circuits comprising: 1) a nonlinear periodically poled two-mode waveguide structure, 2) a set of single-mode and two-mode waveguide-based couplers arranged in such a way that they suitably separate the three photons comprising the SPDC process, and, for some applications, 3) a holographic Bragg grating that acts as a dichroic reflector. The first circuit produces frequency-degenerate down-converted photons, each with even spatial parity, in two separate single-mode waveguides. Changing the parameters of the elements allows this same circuit to produce two nondegenerate down-converted photons that are entangled in frequency or simultaneously entangled in frequency and polarization. The second photonic circuit is designed to produce modal entanglement by distinguishing the photons on the basis of their frequencies. A modified version of this circuit can be used to generate photons that are doubly entangled in mode number and polarization. The third photonic circuit is designed to manage dispersion by converting modal, spectral, and polarization entanglement into path entanglement

Randomly poled crystals as a source of photon pairs

Generation of photon pairs from randomly poled nonlinear crystals is investigated using analytically soluble model and numerical calculations. Randomly poled crystals are discovered as sources of entangled ultra broad-band signal and idler fields. Their photon-pair generation rates scale linearly with the number of domains. Entanglement times as short as several fs can be reached. Comparison with chirped periodically-poled structures is given and reveals close similarity.Comment: 13 pages, 29 figure

Exciton-polariton emission from organic semiconductor optical waveguides

We photo-excite slab polymer waveguides doped with J-aggregating dye molecules and measure the leaky emission from strongly coupled waveguide exciton polariton modes at room temperature. We show that the momentum of the waveguide exciton polaritons can be controlled by modifying the thickness of the excitonic waveguide. Non-resonantly pumped excitons in the slab excitonic waveguide decay into transverse electric and transverse magnetic strongly coupled exciton waveguide modes with radial symmetry. These leak to cones of light with radial and azimuthal polarizations

Effect of W, LR, and LM Tests on the Performance of Preliminary Test Ridge Regression Estimators

This paper combines the idea of preliminary test and ridge regression methodology, when it is suspected that the regression coefficients may be restricted to a subspace. The preliminary test ridge regression estimators (PTRRE) based on the Wald (W), Likelihood Ratio (LR) and Lagrangian Multiplier (LM) tests are considered. The bias and the mean square errors (MSE) of the proposed estimators are derived under both null and alternative hypotheses. By studying the MSE criterion, the regions of optimality of the estimators are determined. Under the null hypothesis, the PTRRE based on LM test has the smallest risk followed by the estimators based on LR and W tests. However, the PTRRE based on W test performs the best followed by the LR and LM based estimators when the parameter moves away from the subspace of the restrictions. The conditions of superiority of the proposed estimator for both ridge parameter k and departure parameter (triangle symbol) are provided. Some graphical representations have been presented which support the findings of the paper. Some tables for maximum and minimum guaranteed relative efficiency of the proposed estimators have been provided. These tables allow us to determine the optimum level of significance corresponding to the optimum estimators among proposed estimators. Finally, we concluded that the optimum choice of the level of significance becomes the traditional choice by using the W test for all non-negative ridge parameter, k.Dominance; Lagrangian Multiplier; Likelihood Ratio Test; MSE; Non-central Chisquare and F; Ridge Regression; Superiority; Wald Test.

Stimulated Emission from a single excited atom in a waveguide

We study stimulated emission from an excited two-level atom coupled to a waveguide containing an incident single-photon pulse. We show that the strong photon correlation, as induced by the atom, plays a very important role in stimulated emission. Additionally, the temporal duration of the incident photon pulse is shown to have a marked effect on stimulated emission and atomic lifetime.Comment: 6 pages, 3 figure

Role of entanglement in two-photon imaging

The use of entangled photons in an imaging system can exhibit effects that cannot be mimicked by any other two-photon source, whatever the strength of the correlations between the two photons. We consider a two-photon imaging system in which one photon is used to probe a remote (transmissive or scattering) object, while the other serves as a reference. We discuss the role of entanglement versus correlation in such a setting, and demonstrate that entanglement is a prerequisite for achieving distributed quantum imaging.Comment: 15 pages, 2 figure

Studi Konflik Air Irigasi dan Alternatif Penyelesaiannya di Daerah Irigasi Kelingi Sumatera Selatan

Study of dispute management related to irrigation water use for agriculture and fishery at Kelingi irrigation area was conducted to determine the irrigation water management solution which is mutually beneficial between rice production and fish production of swift water pond. Kelingi Irrigation Area which is formerly planned for rice cultivation was built during the Dutch colonial era. Former water management pattern and its instruments were incapable to balance the rapid development found in the field which results in interest dispute among the water users. The study methods were consisted of PRA, interview by using questioner aids, and discussion/round table. Dispute management of irrigation water use for agriculture and fishery can be approached by using collaboration system in which all parties gain the advantage because this system is a truly and permanent solution. The recommendations from this study were as follows: 1) irrigation system improvement and increased service capability of the existing irrigation network, 2) balance planting pattern regulation and rice planting schedule as well as cultivation of fish and swift water pond fish at irrigation area level which was decided by using Decree Letter of Governor because this area was classified as district/city crossed irrigation, 3) farmers group empowerment and P3A/GP3A by related councils and institutions, 4) government provision for communication and collaboration between farmers and owner of swift water fish pond through justice and strict approaches in applying the existed regulations, 5) issuing of Local Irrigation Regulation at Province and District/City levels which consisted of swift water fish pond and irrigation water allotments, and 6) law enforcement in permit, supervision and action for every transgression by water users based on Local Regulation and the existed legislation

Quantum Holography

We propose to make use of quantum entanglement for extracting holographic information about a remote 3-D object in a confined space which light enters, but from which it cannot escape. Light scattered from the object is detected in this confined space entirely without the benefit of spatial resolution. Quantum holography offers this possibility by virtue of the fourth-order quantum coherence inherent in entangled beams.Comment: 7 pages, submitted to Optics Expres

Studi Konflik Air Irigasi dan Alternatif Penyelesaiannya di Daerah Irigasi Kelingi Sumatera Selatan

Study of dispute management related to irrigation water use for agriculture and fishery at Kelingi irrigation area was conducted to determine the irrigation water management solution which is mutually beneficial between rice production and fish production of swift water pond. Kelingi Irrigation Area which is formerly planned for rice cultivation was built during the Dutch colonial era. Former water management pattern and its instruments were incapable to balance the rapid development found in the field which results in interest dispute among the water users. The study methods were consisted of PRA, interview by using questioner aids, and discussion/round table. Dispute management of irrigation water use for agriculture and fishery can be approached by using collaboration system in which all parties gain the advantage because this system is a truly and permanent solution. The recommendations from this study were as follows: 1) irrigation system improvement and increased service capability of the existing irrigation network, 2) balance planting pattern regulation and rice planting schedule as well as cultivation of fish and swift water pond fish at irrigation area level which was decided by using Decree Letter of Governor because this area was classified as district/city crossed irrigation, 3) farmers group empowerment and P3A/GP3A by related councils and institutions, 4) government provision for communication and collaboration between farmers and owner of swift water fish pond through justice and strict approaches in applying the existed regulations, 5) issuing of Local Irrigation Regulation at Province and District/City levels which consisted of swift water fish pond and irrigation water allotments, and 6) law enforcement in permit, supervision and action for every transgression by water users based on Local Regulation and the existed legislation.Keywords: irrigation water dispute, rice, swift water pondDiterima: 7 September 2009; Disetujui: 18 Januari 201