scispace - formally typeset
Search or ask a question

Showing papers on "Beam splitter published in 2002"


Journal ArticleDOI
TL;DR: In this paper, it was shown that nonclassicality of the input Gaussian fields is a necessary condition for entanglement of the field modes with the help of a beam splitter.
Abstract: A beam splitter is a simple, readily available device which can act to entangle output optical fields. We show that a necessary condition for the fields at the output of the beam splitter to be entangled is that the pure input states exhibit nonclassical behavior. We generalize this proof for arbitrary (pure or impure) Gaussian input states. Specifically, nonclassicality of the input Gaussian fields is a necessary condition for entanglement of the field modes with the help of a beam splitter. We conjecture that this is a general property of beam splitters: Nonclassicality of the inputs is a necessary condition for entangling fields in a beam splitter.

483 citations


Journal ArticleDOI
TL;DR: The single photon plays a role of a "catalyst:" it is explicitly present in both the input and the output channels of the interaction yet facilitates generation of a nonclassical state of light.
Abstract: We report preparation and characterization of coherent superposition states t[0>+alpha]1> of the electromagnetic field by conditional measurements on a beam splitter. This state is generated in one of the beam splitter output channels if a coherent state [alpha> and a single-photon Fock state [1> are present in the two input ports and a single photon is registered in the other beam splitter output. The single photon thus plays a role of a "catalyst:" it is explicitly present in both the input and the output channels of the interaction yet facilitates generation of a nonclassical state of light.

182 citations


Journal ArticleDOI
TL;DR: In this article, a beam splitter of reflectivity one third can be used to realize a quantum phase gate operation if only the outputs conserving the number of photons on each side are postselected.
Abstract: We show that a beam splitter of reflectivity one-third can be used to realize a quantum phase gate operation if only the outputs conserving the number of photons on each side are postselected.

154 citations


Journal ArticleDOI
TL;DR: Kim et al. as discussed by the authors proved that the entangled output state from a beam splitter requires nonclassicality in the input state, and they gave a proof for this conjecture.
Abstract: It has been conjectured that the entangled output state from a beam splitter requires nonclassicality in the input state [M. S. Kim, W. Son, V. Buzek, and P. L. Knight, Phys. Rev. A 65, 032323 (2002)]. Here we give a proof for this conjecture.

147 citations


Journal ArticleDOI
TL;DR: The fundamental features of an interferometer for guided matter waves, built of two combined Y-shaped beam splitters, are described, and it is found that such a device is expected to exhibit high contrast fringes even in a multimode regime, analogous to a white light interferometers.
Abstract: Atoms can be trapped and guided with electromagnetic fields, using nanofabricated structures. We describe the fundamental features of an interferometer for guided matter waves, built of two combined Y-shaped beam splitters. We find that such a device is expected to exhibit high contrast fringes even in a multimode regime, analogous to a white light interferometer.

136 citations


Journal ArticleDOI
TL;DR: An experimentally realized set of operations on a single trapped ion is sufficient to simulate a wide class of Hamiltonians of a spin-1/2 particle in an external potential and the use of nonlinear beam splitters enhances this sensitivity compared to the standard quantum limit imposed by a linear beam splitter.
Abstract: We show how an experimentally realized set of operations on a single trapped ion is sufficient to simulate a wide class of Hamiltonians of a spin-$1/2$ particle in an external potential. This system is also able to simulate other physical dynamics. As a demonstration, we simulate the action of two $n\mathrm{t}\mathrm{h}$ order nonlinear optical beam splitters comprising an interferometer sensitive to phase shift in one of the interferometer beam paths. The sensitivity in determining these phase shifts increases linearly with $n$, and the simulation demonstrates that the use of nonlinear beam splitters ($n=2,3$) enhances this sensitivity compared to the standard quantum limit imposed by a linear beam splitter ($n=1$).

135 citations


Journal ArticleDOI
TL;DR: In this article, the nonlinearities in a heterodyne laser interferometer system occurring from the phase measurement system of the interferometers and from non-ideal polarization effects of the optics are modeled into one analytical expression which includes the initial polarization state of the laser source, the rotational alignment of the beam splitter along with different transmission coefficients for polarization states and rotational misalignment of the receiving polarizer.
Abstract: The non-linearities in a heterodyne laser interferometer system occurring from the phase measurement system of the interferometer and from non-ideal polarization effects of the optics are modeled into one analytical expression which includes the initial polarization state of the laser source, the rotational alignment of the beam splitter along with different transmission coefficients for polarization states and the rotational misalignment of the receiving polarizer. The model is verified using a Babinet Soleil Compensator allowing a common path for both polarization states and thereby reducing the influence of the refractive index of air. The verification shows an agreement of the model with measurements with a standard deviation of 0.2 nm. With the use of the model it is confirmed that the mean of two polarizer receivers can reduce the effect of non-linearity. However, depending on the accuracy of the polarizer angles, a second-order non-linearity remains. Also the effect of rotational misalignment of the beam splitter can not be reduced in this way.

134 citations


Journal ArticleDOI
TL;DR: In this article, the authors proposed a scheme for conditional generation of two-mode N-photon path-entangled states of traveling light field, which may find applications in quantum optical lithography and they may be used to improve the sensitivity of interferometric measurements.
Abstract: We propose a scheme for conditional generation of two-mode N-photon path-entangled states of traveling light field. These states may find applications in quantum optical lithography and they may be used to improve the sensitivity of interferometric measurements. Our method requires only single-photon sources, linear optics (beam splitters and phase shifters), and photodetectors with single-photon sensitivity.

125 citations


Journal ArticleDOI
TL;DR: In this article, the authors synthesized displaced Fock states of the electromagnetic field by overlapping the pulsed optical single-photon Fock state with coherent states on a high-reflection beam splitter and completely characterized by means of quantum homodyne tomography.
Abstract: Displaced Fock states of the electromagnetic field have been synthesized by overlapping the pulsed optical single-photon Fock state $|1〉$ with coherent states on a high-reflection beam splitter and completely characterized by means of quantum homodyne tomography. The reconstruction reveals nonclassical properties of displaced Fock states, such as negativity of the Wigner function and photon number oscillations. To our knowledge, this is the first time complete tomographic reconstruction has been performed on a highly nonclassical optical state.

120 citations


Journal ArticleDOI
TL;DR: In this paper, polarization beam-splitters and optical switches based on subwavelength quasi-periodic structures are presented. And they show experimental results for infra-red radiation at a wavelength of 10.6 μm.

118 citations


Patent
12 Apr 2002
TL;DR: In this paper, a light projection engine uses a wide angle reflecting polarizer material (preferably 3M DBEF brand double brightness enhancement filter) as a polarizing beamsplitter to direct polarized light to beam splitter/combiner (such as an X-cube dichroic reflector).
Abstract: A light projection engine uses a wide angle reflecting polarizer material (preferably 3M DBEF brand double brightness enhancement filter) as a polarizing beamsplitter to direct polarized light to beam splitter/combiner (such as an X-cube dichroic reflector). The beam splitter/combiner then splits the directed polarized light into separate reflective LCD panels acting as light valves. The LCD panels alter the polarity of the incident light from 0 degrees up to 90 degrees to control which light is passes from the wide angle reflecting polarizer back towards the light source and which light has the necessary polarization change to allow it to pass from the wide angle reflecting polarizer to the lens system. After reflecting off of the LCD panels, the light goes back through the X-cube dichroic reflector, where it is recombined. The recombined light which is of a first polarity is transmitted from the reflecting polarizer to the lens system, while the recombined light which is of a second polarity is transmitted to the light source. The LCDs are preferably analog polarizing LCDs.

Journal ArticleDOI
TL;DR: This work reports the first direct experimental characterization of continuous variable quantum Stokes parameters and generates a continuous wave light beam with more than 3 dB of simultaneous squeezing in three of the four Stokes parameter.
Abstract: We report the first direct experimental characterization of continuous variable quantum Stokes parameters. We generate a continuous wave light beam with more than 3 dB of simultaneous squeezing in three of the four Stokes parameters. The polarization squeezed beam is produced by mixing two quadrature squeezed beams on a polarizing beam splitter. Depending on the squeezed quadrature of these two beams the quantum uncertainty volume on the Poincare sphere becomes a “cigarlike” or “pancakelike” ellipsoid.

Journal ArticleDOI
TL;DR: Multisimultaneity is a causal model of relativistic quantum physics which assigns a real time ordering to any set of events, much in the spirit of the pilot-wave picture, which predicts a disappearance of the correlations in a Bell-type experiment when both analyzers are in relative motion.
Abstract: Multisimultaneity is a causal model of relativistic quantum physics which assigns a real time ordering to any set of events, much in the spirit of the pilot-wave picture. Contrary to standard quantum mechanics, it predicts a disappearance of the correlations in a Bell-type experiment when both analyzers are in relative motion such that each one, in its own inertial reference frame, is first to select the output of the photons. We tested this prediction using acousto-optic modulators as moving beam splitters and interferometers separated by 55 m. We did not observe any disappearance of the correlations, in agreement with quantum mechanics.

Journal ArticleDOI
TL;DR: In this paper, the authors presented a scheme to produce an entangled four-photon W state by using linear optical elements, which consists of four beam splitters, four polarization beam splitter, and four mirrors.
Abstract: We present a scheme to produce an entangled four-photon W state by using linear optical elements. The symmetrical setup of linear optical elements consists of four beam splitters, four polarization beam splitters, and four mirrors. A photon Einstein-Podolsky-Rosen pair and two single photons are required as the input modes. The projection on the W state can be made by a four-photon coincidence measurement. Further, we show that by means of a horizontally oriented polarizer in front of one detector, the W state of three photons can be generated.

Proceedings ArticleDOI
25 Jun 2002
TL;DR: The photo-thermo-refractive (PTR) glass as mentioned in this paper is a PTR glass in which Bragg gratings (holograms) can be written in the interior (not the surface) of the glass.
Abstract: A new material for optics is being developed that promises to be far more robust than alternative materials. It is a photo-thermo-refractive (PTR) glass in which Bragg gratings (holograms) can be written in the interior (not the surface) of the glass. The gratings are permanent as they are not removed by illuminating them with light at other wavelengths or by heating unless the temperature exceeds 400 degree(s)C. This technology can be used to make diffractive elements such as spatial filters, attenuators, switches, modulators, beam splitters, beam samplers, beam deflectors, selectors of particular wavelengths (notch filters, add/drop elements), spectral shape formers (gain equalizers), spectral sensors, angular sensors, Bragg spectrometers, and transverse and longitudinal mode selectors in a laser resonator. The PTR Bragg grating has been exposed to a 100 W, 1096 nm beam focused to 100 kW/cm2 spot for 10 minutes without exhibiting any temperature rise. The pulsed laser damage threshold has been measured to be within 30% of that of the best silica glass used in high power 1064 nm systems. The useful spectral range of this glass is from 350 nm to 2.8 microns.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Journal ArticleDOI
TL;DR: The device has a large splitting angle of 120 degrees and a miniature size and the Y-splitter loss is measured to be 0.5-1 dB at lambda=1640-1680 nm, making the Y splitter promising for integrated photonic-circuit applications.
Abstract: We report a successful experimental realization of a photonic-crystal Y splitter operating at lambda~1.6 mum . Our device has a large splitting angle of 120 degrees and a miniature size of ~3 mumx3 mum . Furthermore, the Y-splitter loss is measured to be 0.5-1 dB at lambda=1640-1680 nm, making the Y splitter promising for integrated photonic-circuit applications. These unique properties are attributed to the new guiding principle made possible by the photonic bandgap.

Journal ArticleDOI
TL;DR: A line of periodic dot structure with an interval of 6.25 μm on a gold thin film was fabricated with a single shot of interfered femtosecond laser beams split by a diffraction beam splitter as mentioned in this paper.
Abstract: A line of periodic dot structure with an interval of 6.25 μm on a gold thin film was fabricated with a single shot of interfered femtosecond laser beams split by a diffraction beam splitter. The total length of the structure was 6 mm. In addition, dot matrix and comb structures were fabricated with transportation of samples at an arbitrary speed during the process. The samples worked as transmission and reflection gratings. In addition, nanowires were fabricated by peeling the comb structure, of which the thickness was 200 nm.

Patent
06 Aug 2002
TL;DR: An optical instrument using a plurality of lasers of different colors with parallel, closely spaced beams to stimulate scattering and fluorescence from fluorescent biological particulate matter, including cells and large molecules.
Abstract: An optical instrument using a plurality of lasers of different colors with parallel, closely spaced beams to stimulate scattering and fluorescence from fluorescent biological particulate matter, including cells and large molecules. A large numerical aperture objective lens collects fluorescent light while maintaining spatial separation of light stimulated by the different sources. The collected light is imaged into a plurality of fibers, one fiber associated with each optical source, which conducts light to a plurality of arrays of detectors, with each array associated with light from one of the fibers and one of the lasers. A detector array has up to ten detectors arranged to separate and measure colors within relatively narrow bands by decimation of light arriving in a fiber. A large number of detectors is mounted in a compact polygonal arrangement by using reflective transfer legs from multiple beam splitters where the transfer legs arise from a polygonal arrangement of beam splitters in a circumference within the circumferential arrangement of detectors.

Patent
15 Jan 2002
TL;DR: The Wavefront Coding optical element can be fabricated as a separate component, can be constructed as an integral component of the imaging objective, tube lens, beam splitter, polarizer or any combination of such as discussed by the authors.
Abstract: Contrast Imaging apparatus and methods with Wavefront Coding aspheric optics and post processing increase depth of field and reduce misfocus effects in imaging Phase Objects. The general Interference Contrast imaging system is modified with a special purpose optical element and image processing of the detected image to form the final image. The Wavefront Coding optical element can be fabricated as a separate component, can be constructed as an integral component of the imaging objective, tube lens, beam splitter, polarizer or any combination of such.

Patent
29 Mar 2002
TL;DR: An optical measurement system for evaluating a sample has a motor-driven rotating mechanism coupled to an azimuthally rotatable measurement head, allowing the optics to rotate with respect to the sample as discussed by the authors.
Abstract: An optical measurement system for evaluating a sample has a motor-driven rotating mechanism coupled to an azimuthally rotatable measurement head, allowing the optics to rotate with respect to the sample. A polarimetric scatterometer, having optics directing a polarized illumination beam at non-normal incidence onto a periodic structure on a sample, can measure optical properties of the periodic structure. An E-O modulator in the illumination path can modulate the polarization. The head optics collect light reflected from the periodic structure and feed that light to a spectrometer for measurement. A beamsplitter in the collection path can ensure both S and P polarization from the sample are separately measured. The measurement head can be mounted for rotation of the plane of incidence to different azimuthal directions relative to the periodic structures. The instrument can be integrated within a wafer process tool in which wafers may be provided at arbitrary orientation.

Journal ArticleDOI
TL;DR: An array of atom waveguides being formed by focusing a red-detuned laser beam with an array of cylindrical microlenses are used to realize X-shaped beam splitters and more complex systems like the geometries for Mach-Zehnder and Michelson-type interferometers for atoms.
Abstract: We experimentally demonstrate interferometer-type guiding structures for neutral atoms based on dipole potentials created by microfabricated optical systems. As a central element we use an array of atom waveguides being formed by focusing a red-detuned laser beam with an array of cylindrical microlenses. Combining two of these arrays, we realize X-shaped beam splitters and more complex systems like the geometries for Mach-Zehnder and Michelson-type interferometers for atoms.

Journal ArticleDOI
TL;DR: In this paper, the authors developed materials for classroom teaching about the quantum behavior of photons in beam splitters as part of a project to create five experiments that use correlated photons to exhibit nonclassical quantum effects vividly and directly.
Abstract: We are developing materials for classroom teaching about the quantum behavior of photons in beam splitters as part of a project to create five experiments that use correlated photons to exhibit nonclassical quantum effects vividly and directly. Pedagogical support of student understanding of these experiments requires modification of the usual quantum mechanics course in ways that are illustrated by the treatment of the beam splitter presented here.

Patent
26 Nov 2002
TL;DR: In this article, color selective polarization filters (CSPs) and polarizing beamsplitters are used in projectors with retarder stack filters to orthogonally polarize primary colors.
Abstract: Beamsplitters are used in projectors with retarder stack filters to orthogonally polarize primary colors, thus converting polarizing beamsplitters to color splitters and combiners. Beamsplitters at moderate f-numbers induce geometric polarization rotations in skew rays which may degrade performance of conventional retarder stacks, resulting in color cross-talk. Retarder stacks presented herein are sensitive to the symmetries between input and output polarizer configurations. These stacks provide the polarization transformations to compensate for skew rays, such that normal incidence performance is maintained for all incident light. Systems are disclosed utilizing color selective polarization filters 'CSP' and polarizing beamsplitters without the need for an output analyzer. The CSP may be included in the above system. One exemplary CSP architecture includes two CSPs (404, 318), a single polarizing beamsplitter/combiner (324) between two (326, 330) of the three panels, and an output polarizing beamsplitter (316) element used as an analyzer such that a single CSP (318) is in the projection path. A second architecture uses an output combining chromatic polarizing beamsplitter. A third architecture uses chromatic sheet polarizers to enhance CSP performance. In all of the architectures, an output CSP and clean-up polarizer directly in front of the projection optics need not be included, thereby increasing transmission, improving imaging crispness by increasing the optical phase flatness of the projecting light, and reducing cost.

Patent
04 Feb 2002
TL;DR: In this article, a hybrid counting/integrating system for processing a signal from a photomultiplier tube was proposed. But the system was not designed for large dynamic range light detection.
Abstract: System for large dynamic range light detection. In one aspect, the system includes a hybrid counting/integrating system for processing a signal from a photomultiplier tube. In another aspect, large dynamic range is achieved in a cascaded detector system utilizing at least one asymmetric beam splitter for delivering a larger fraction of incident light to one photomultiplier tube and for delivering a smaller fraction of the incident light to another photomultiplier tube.

Patent
18 Nov 2002
TL;DR: A power-saving method with integrated photodiode light source was proposed in this paper, where a light control circuit is used to control light beam from the light source illuminating a reflector and then reflecting to a reflective display panel in order to reflect the light beam.
Abstract: A power-saving method with integrated photodiode light source. This device has a circuit board with a plurality of red, green and blue photodiodes as the device's light source. Additionally, a light control circuit is used to control light beam from the light source illuminating a reflector and then reflecting to a reflective display panel in order to reflect the light beam and generate an image. Thus, a projection module can project the image on a viewing plate. As cited, the inventive device includes: a light control circuit, a light source module, a polarizing beam splitter (PBS), a reflective display panel and a projection module.

Patent
21 Jun 2002
TL;DR: In this article, a beam splitter is used to select the sate of reference light and the state of object light to be selectively regulated into any one of the four ways of horizontal linear polarized light, vertical linearly polarized light and right-handed circularly polarized light.
Abstract: PROBLEM TO BE SOLVED: To verify fine structures including birefringence distribution which has not been acquired by a conventional OCT (optical coherence tomography) measurement in the measurement of cross-sectional structures of biosamples including the birefringence distribution such as fish bones and human skin. SOLUTION: The sate of reference light and the state of object light are each selectively regulated into any one of the four ways of horizontal linear polarized light, vertical linearly polarized light, 45° linearly polarized light, and right-handed circularly polarized light. Each state of polarized light is combined by a beam splitter 10 into sixteen-way combinations of four by four, and is passed through a spectroscope having a diffraction grating 20 and lenses. Its interference fringes are photographed by a CCD camera 22 to acquire sixteen coherence tomographic images. By determining each element of the Mueller matrix capable of displaying the polarization characteristics of the sample from the sixteen coherence tomographic images, the polarization information inside the sample is measured. COPYRIGHT: (C)2004,JPO

Patent
05 Jun 2002
TL;DR: In this article, a display apparatus including a light source and a pre-polarizer for forming a beam of light (130) was used to provide a polarized beam of illumination.
Abstract: A display apparatus ( 10 ) including a light source ( 15 ) for forming a beam of light ( 130 ). A pre-polarizer ( 45 ) polarizes the beam of light ( 130 ) to provide a polarized beam of light. A wire grid polarization beamsplitter ( 50 ) receives the polarized beam of light and transmits the polarized beam of light which has a first polarization, and reflects the polarized beam of light which has a second polarization. A reflective spatial light modulator ( 55 ) selectively modulates the polarized beam of light that has a first polarization to encode image data thereon in order to form a modulated beam ( 360 ) and reflects the modulated beam back to the wire grid polarization beamsplitter ( 50 ). A compensator ( 260 ) is located between the wire grid polarization beamsplitter ( 50 ) and the reflective spatial light modulator ( 55 ) for conditioning oblique and skew rays of the modulated beam ( 360 ). The wire grid polarization beamsplitter ( 50 ) reflects the compensated modulated beam ( 360 ) and the wire gird polarization beamsplitter ( 50 ) is rotated in plane to optimize the contrast. A polarization analyzer ( 60 ) removes residual light of the opposite polarization state from the compensated modulated beam ( 360 ). Image-forming optics ( 20 ) form an image from the compensated modulated beam ( 360 ).

Journal ArticleDOI
TL;DR: In this article, the integrated waveguide turning mirror (IWTM) is designed with a 90/spl deg/ directional change in silicon-on-insulator (SOI) and fabricated mirror has very small surface roughness.
Abstract: Planar lightwave circuits based on silicon are playing an important role in integrated optical systems. The integrated waveguide turning mirror (IWTM) is an essential component for the compactness of optical devices. We have designed such a mirror with a 90/spl deg/ directional change in silicon-on-insulator (SOI). The fabricated mirror has very small surface roughness. The loss caused by transverse tilt /spl delta//sub t/ and lateral tilt /spl delta//sub l/ is negligible in theory. A 1 /spl times/ 2 beam splitter using the structure is fabricated to test the performance, and turning mirrors of excess loss less than 0.5 dB/mirror are obtained.

Patent
06 Aug 2002
TL;DR: A color management system for use with projection displays includes a separating polarizing beamsplitter, a compensating prism group, an image assimilator, and a combining polarizing beam splitter.
Abstract: A color management system for use with projection displays includes, for example, a separating polarizing beamsplitter, a compensating prism group, an image assimilator, and a combining polarizing beam splitter. In accordance with an exemplary embodiment, the separating polarizing beamsplitter receives a bi-oriented light input and separates it into two output beams, one comprising a first component and the other comprising a second component. The image assimilator receives an output light beam from the separating polarizing beamsplitter, transmits the light output to one or more corresponding microdisplays, receives one or more modified outputs from the microdisplays, and emits an output comprising those modified outputs to a combining polarizing beamsplitter. The compensating prism group receives from the separating polarizing beamsplitter the other output light beam, transmits it to another corresponding microdisplay, receives from the microdisplay a modified light output, and transmits it to the combining polarizing beamsplitter be combined with the light output from the image assimilator. The compensating prism group may be configured to compensate for an optical aberration induced by the light separator.

Patent
08 Mar 2002
TL;DR: In this paper, a dispersive, diffraction grating, NIR spectrometer that automatically calibrates the wavelength scale of the instrument without the need for external wavelength calibration materials is presented.
Abstract: The present invention is a dispersive, diffraction grating, NIR spectrometer that automatically calibrates the wavelength scale of the instrument without the need for external wavelength calibration materials. The invention results from the novel combination of: 1) a low power He—Ne laser at right angles to the source beam of the spectrometer; 2) a folding mirror to redirect the collimated laser beam so that it is parallel to the source beam; 3) the tendency of diffraction gratings to produce overlapping spectra of higher orders; 4) a “polka dot” beam splitter to redirect the majority of the laser beam toward the reference detector; 5) PbS detectors and 6) a software routine written in Lab VIEW that automatically corrects the wavelength scale of the instrument from the positions of the 632.8 nm laser line in the spectrum.