Reading Beam Research Articles

Research of light diffraction on electrically controlled multiplexed multilayer inhomogeneous holographic diffraction structures based on the photopolymerizing compositions with nematic liquid crystals

We presented the developed analytical model of optical radiation diffraction on multiplexed multilayer inhomogeneous diffraction structures formed by the holographic method in photopolymerizing compositions with nematic liquid crystals having smooth optical heterogeneity in the thickness of the layers. By numerical calculation, it was shown that when using an applied electric field with different polarities to the diffraction layers, as well as varying the azimuth of the polarization of the reading beam, the angular selectivity of the diffracted beam can be transformed with a significant shift in angular selectivity, which makes it possible to increase the spectral bandwidth by 4 times compared to conventional multilayer diffraction structures.

Multiplexed digital volume reflection holograms generated from digital transmission holograms.

Interference from co-propagation of the object and reference beams can be digitally recorded for a digital transmission hologram (DTH). Volume holograms, as in display holography, which have been traditionally recorded in bulk photopolymer or photorefractive materials using a counter-propagating object and writing beams, are read out using multispectral light and offer the advantage of excellent wavelength selectivity. In this work, the reconstruction from a single digital volume reflection hologram (DVRH) and wavelength multiplexed DVRHs derived from respective single and multi-wavelength DTHs is investigated, using coupled wave theory and an angular spectral approach. The dependence of the diffraction efficiency on volume grating thickness, wavelength, and incident angle of the reading beam is studied.

Orbital Angular Momentum Multiplexing Holography for Data Storage

In the letter, we propose a holographic data storage method based on orbital angular momentum (OAM). In the proposed method, the OAM holography by discovering strong OAM selectivity in the spatial-frequency domain without a theoretical helical mode index limit is used to label different data pages. Each data page’s points and intensity levels are used to store the information. The data page can be reconstructed by using an OAM reading beam with an inverse helical mode illuminating the OAM-recording hologram. To further increase the density, different OAM-recording holograms are multiplexed. The experimental results show that we can store and read out the data by using the OAM hologram, and the density can be greatly improved by using the OAM-multiplexing hologram.

Generation of highly retrievable atom photon entanglement with a millisecond lifetime via a spatially multiplexed cavity

Qubit memory that is entangled with photonic qubit is the building block for long distance quantum repeaters. Cavity enhanced and long lived spin wave photon entanglement has been demonstrated by applying dual laser beams onto optical-lattice atoms. However, owing to cross readouts by two beams, retrieval efficiency of spin wave qubit is decreased by one quarter compared to that of single mode spin wave at all storage times. Here, by coupling cold atoms to two modes of a polarization interferometer based cavity, we achieve perfect qubit retrieval in cavity enhanced and long lived atom photon entanglement. A write laser beam is applied onto cold atoms, we then create a magnetic field insensitive spin wave qubit that is entangled with the photonic qubit encoded onto two arms of the interferometer. The spin wave qubit is retrieved by a read beam, which avoids the cross readouts. Our experiment demonstrates 540μs storage time at 50% intrinsic qubit retrieval efficiency, which is 13.5 times longer than the best reported result.

Using molecules as a quantum interface to store ultrashort optical vortices

We exploit gas-phase molecules as light-matter interface to store an orbital angular momentum (OAM) or a superposition of OAM states (OAM-based photonic qubits) carried by ultrashort laser pulses. The interplay between spin angular momentum and OAM is exploited to encode the amplitude and spatial phase information of light beams into rotational coherences of molecules. This last is restored on-demand over tens of picoseconds with a reading beam by taking advantage of field-free molecular alignment. The underlying mechanism at the origin of the storage can be interpreted by the spatial structuring of the molecular sample induced by the field. The excitation indeed produces an inhomogeneous spatial distribution of molecular alignment (amplitude & orientation) whose periodical revivals associated with the quantum beatings of the rotational wavepacket enables to restore the spatial beam structure on-demand. The strategy is successfully demonstrated in CO2 molecules at room temperature. Besides applicability as storage medium with THz bandwidth application, the use of molecules as light-matter interface opens new functionalities in terms of optical processing and versatile control of OAM fields.

Dependence of retrieval efficiency on waist ratio of read beam to anti-Stokes photon mode in cavity-enhanced quantum memory

<sec>Quantum communication is promising for absolutely safe information transmission. However, the direct transmission distance of quantum states is limited by the no-cloning theorem and transmission loss. To solve these problems, Duan et al. proposed a promising quantum repeater scheme, DLCZ protocol (Duan L M, Lukin M D, Cirac J I, Zoller P <ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://doi.org/10.1038/35106500">2001 <i>Nature</i> <b>414</b> 413</ext-link>), in which linear optics and atomic ensembles are used to combine entanglement generation and quantum memory into a single node. A quantum memory with highly retrieval efficiency is beneficial to increasing the rate of entanglement swapping, and also achieving high-speed entanglement distribution. Up to now, high-efficiency quantum memories have been realized by using high-optical-depth atomic ensembles or by coupling atomic ensembles with a medium-finesse optical cavity. However, the effect of the waist ratio of read beam mode and anti-Stokes photon mode on intrinsic retrieval efficiency has not been studied in detail. Here, we study the dependence of intrinsic retrieval efficiency on the waist ratio of read beam mode to anti-Stokes photon mode in cavity-enhanced quantum memory.</sec><sec>In this work, an <sup>87</sup>Rb atomic ensemble, that is placed at the center of a passively stabilized polarization interferometer (BD<sub>1,2</sub>), is used as quantum memory. Firstly, the ensemble is captured through magneto-optical trapping (MOT) and prepared into the Zeeman sub-level of ground state <inline-formula><tex-math id="M4">\begin{document}$ \left| {5{{\text{S}}_{{1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}}},F = 1,m = 0} \right\rangle $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M4.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M4.png"/></alternatives></inline-formula>. Then, a weak write pulse with frequency red-detuned from the <inline-formula><tex-math id="M5">\begin{document}$ \left| {5{{\text{S}}_{{1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}}},F = 1,m = 0} \right\rangle \to \left| {5{{\text{P}}_{{1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}}},F' = 1,m = 1} \right\rangle $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M5.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M5.png"/></alternatives></inline-formula> transition by 110 MHz, illuminates the atoms and induces spontaneous Raman scattering out a Stokes photon. In this regime of weak excitation, the detection of a Stokes photon heralds the storage of a single spin wave <inline-formula><tex-math id="M6">\begin{document}$ \left| {5{{\text{S}}_{{1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}}},F = 1,m = 0} \right\rangle \leftrightarrow \left| {5{{\text{S}}_{{1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}}},F = 2,m = 0} \right\rangle $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M6.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M6.png"/></alternatives></inline-formula> (<inline-formula><tex-math id="M7">\begin{document}$ \left| {5{{\text{S}}_{{1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}}},F = 1,m = 0} \right\rangle \leftrightarrow \left| {5{{\text{S}}_{{1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}}},F = 2,m = 2} \right\rangle $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M7.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M7.png"/></alternatives></inline-formula>) distributed among the whole ensemble. After a programmable delay, a read pulse that generates a 110 MHz red-detuning from the <inline-formula><tex-math id="M8">\begin{document}$ \left| {5{{\text{S}}_{{1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}}},F = 2,m = 0} \right\rangle \to \left| {5{{\text{P}}_{{1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}}},F' = 2,m = - 1} \right\rangle $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M8.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M8.png"/></alternatives></inline-formula> transition converts this spin wave into an anti-Stokes photon. We detect the Stokes photons and anti-Stokes photons with polarization <inline-formula><tex-math id="M9">\begin{document}$ {\sigma ^ + } $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M9.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M9.png"/></alternatives></inline-formula>, which means that all the spin-waves are stored in a magnetic-field-insensitive state to reduce the decoherence caused by the stray magnetic fields. In order to increase the intrinsic retrieval efficiency, the atomic ensemble is placed in a ring cavity. The cavity length is 4 m, the finesse is measured to be ~15, and the escape efficiency of ring cavity is 52.9%. Both Stokes and anti-Stokes photon qubits are required to resonate with the ring cavity. To meet this requirement, a cavity-locking beam is injected into the cavity to stabilize the cavity length by using a Pound-Drever-Hall locking scheme. Finally, we fix the Stokes (anti-Stokes) photon mode waist and change the waist ratio through changing the write beam (read beam) waist.</sec><sec>The experimental results show that when the waist ratio of read beam mode to anti-Stokes photon mode is 3, the intrinsic retrieval efficiency reaches to <inline-formula><tex-math id="M10">\begin{document}$ 68.9 {\text{%}} \pm 1.6{\text{%}} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M10.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M10.png"/></alternatives></inline-formula> and normalized cross-correlation function <inline-formula><tex-math id="M11">\begin{document}$ {g^{(2)}} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M11.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M11.png"/></alternatives></inline-formula> can achieve <inline-formula><tex-math id="M12">\begin{document}$ 26.5 \pm 1.9 $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M12.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20230966_M12.png"/></alternatives></inline-formula>. We build a theoretical model, which shows that the intrinsic retrieval efficiency reaches the peak when the waist ratio is 3, and the intrinsic retrieval efficiency tends to be stable when the waist ratio continues to increase. The experimental results accord with the theoretical results. In the future, we will improve the intrinsic retrieval efficiency by enhancing the fineness of the optical cavity with optimal cavity parameters.</sec>

Molecular Quantum Interface for Storing and Manipulating Ultrashort Optical Vortex

AbstractLight beams carrying orbital angular momentum (OAM) have become over the past few years a subject of widespread interest with unprecedented applications in various fields such as optical communication, super‐resolution imaging, optical tweezers, or quantum processing. In the present work it is demonstrated that gas‐phase molecules can be used as a quantum interface to store an OAM carried by an ultrashort laser pulse. The interplay between spin angular momentum and OAM is exploited to encode the spatial phase information of light beams into rotational coherences of molecules. The embedded spatial structure is restored on‐demand with a reading beam by taking advantage of field‐free molecular alignment. The strategy is successfully demonstrated in CO2 molecules at room temperature. Apart from applications to broadband coherent buffer memory, this method opens new functionalities in terms of optical processing and versatile control of OAM fields as well as for a deeper understanding of their role on various molecular processes.

The Training of Reading Beam Notations on Pranada Lines for Children in the Community Reading Park

Block notation is one of the elements in music. Creativity in singing needs to be trained from an early age, with interest and talent, creativity is also very influential with experience. The purpose of this community service implementation is to provide training to read block notation on the rhyme line for children at the community reading park (TBM) in order to children are accustomed to seeing block notation from an early age, students are able to differentiate the tone "do" to tone "re" to tone "mi" and so on, so it is not new thing for students to see the notation of blocks on the sheet music. The implementation method of this community service using the lecture method, demonstration method and practice (data is in qualitative form with descriptive methods) by describing the data in detail and in detail in accordance with the implementation of community service activities. This training explains the shape of block notation, symbols in music, the symbol functions to determine the high and low of the voice, beam notation is divided into 3 parts consisting of flags, stems, and notation heads. Furthermore , it provides training on the value, shape and location of the beat on the line. From this community service activity, the authors got the results, namely: 1) adding knowledge to students in the form of block notation, 2) students being able to read block notation with slash lines and distinguishing the shape and location of tones on the rhyme line, 3) developing interest and students’ talent to appear in front of their friends to sing, 4) students are able to make block notation well, 5) this training produces students who are able to practice solfegio exercises well, 6) this training is participated by elementary school students consists of low class and high class.

SIGHT SINGING SEBAGAI STRATEGI PEMBELAJARAN INSTRUMEN PIANO DI PRODI PENDIDIKAN MUSIK ISI YOGYAKARTA

Sight Singing is the ability to read the notation and immediately sing the tune in accordance with the melody on the sheet music. Sight Singing is the activity of singing with solmisasi or movabel "do". This study aims to improve the ability to read beam notation in learning mandatory piano instruments using the Sight Singing approach. The Mandatory Piano Instrument course is one of the practical courses that must be taken by all Music Education Study Program students, ISI Yogyakarta. Not all new students in Music Education Study Program can read the beam notation, so this Piano Compulsory Instrument course course is always feared by students who have not read fluent notation. Sight singing as a strategy to enhance the learning of Piano Mandatory Instruments. This research is focused on the application of Sight singing in learning Mandatory Piano Instruments in Music Education Study Program. This research uses Classroom Action Research which can be categorized as a qualitative-experimental research by applying the Sight singing method. The results of this study are the learning process of the Mandatory Piano Instrument with the application of the Sight singing method more effectively to improve the ability to learn to read notation while playing the Piano Instrument, and students can be more expressing, impressed singing by accompanying themselves.

Application of the cepstrum method for processing iridology television signals

The questions of the cepstrum method application for the processing of iridology television signals are considered. A cepstrum method for processing a delayed video signal of an aerospace television system is proposed. The application of the method greatly facilitates the determination of the delay and expands the dynamic range of the corrected signal. An expression for determining the power cepstrum at different apertures of the reading beam is received and a suboptimal model of an ideal corrector is designed. Keywords aperture correction; digital correction; linear and nonlinear correctors; cepstrum method; aperture; Gaussian aperture; exponential aperture; signal power cepstrum

Faber Method Classical Piano Learning In Purwacaraka Music School Purwokerto

Purwacaraka Purwokerto Music School is able to give birth to talented classical piano students so they can win various championships. From the observations, this is influenced by the use of the faber method in learning. This study aims to describe learning methods faber at Purwacaraka Purwokerto Music School. The research approach applied in this study is descriptive qualitative. Data collection techniques are carried out by observation, interview and document study. The results of this study indicate that the use of the faber method in classical piano learning in Purwacaraka Purwokerto Music School is only used at the beginner level (Grade Preparatory) and is an excellent method for learning at the beginner level because it uses books specifically designed for beginners with many bring up colorful images that make students imagine, so students understand learning material in their own way. The advantages of the faber method are that students get a strong foundation in reading beam notation, dynamics games and articulation in a score of songs played and this method is a very good method used as a basis for learning piano because it has material and theory that is emphasized to provide basic reference piano playing with piano playing techniques.

IMPLEMENTASI METODE SUZUKI DALAM PEMBELAJARAN BIOLA TINGKAT DASAR DI ERA MUSIKA MEDAN

This study aims to describe the implementation of basic level violin learningusing the Suzuki method in the Medan Musika Era. The subjects in this study were students who tookviolin instruments in the Medan Musika Era. This study focused on the problems associated with theimplementation of basic level violin learning with the Suzuki method, which was viewed from theprocess of the steps of the study. This study used descriptive qualitative research methods, namelya research method that aims to describe in detail and clearly about a phenomenon which is the focusof research. The results of the research on the implementation of basic level violin learning usingthe Suzuki method in the Medan Musika Era show as follows (1) Education 'starts at a very earlyage by not limiting students who learn violin in the Musika Era. (2) Prioritizing to teach students tolisten to just play a musical instrument, by the way the teacher demonstrates the song learned by thenew student, the student mimics the song. (3) Violin learning takes place by giving songs that are inSuzuki's books repeatedly. (4) Learning to read beam notation using fingering in accordance withwhat is in the Suzuki method book.

Holographic Formation of Diffraction Elements for Transformation of Light Beams in Liquid Crystal – Photopolymer Compositions

A theoretical model of holographic formation of diffractive optical elements for transformation of light beam field into Bessel-like fields in liquid crystal – photopolymer (LC–PPM) composite materials with a dyesensitizer is developed. Results of numerical modeling of kinetics ofvariation of the refractive index of a material in the process of formation with different relationships between the photopolymerization rates and diffusion processes are presented. Based on the results of numerical simulation, it is demonstrated that when the photopolarization process dominates, the diffractive element being formed is distorted. This leads to a change in the light field distribution at its output and consequently, to ineffective transformation of the reading beam. Thus, the necessity of optimizing of the recording conditions and of the prepolymeric composition to increase the transformation efficiency of light beam fields is demonstrated.

Nonlinear optical memory: theory and experiment

The present work explores new possibilities for the selective storage of optical information through higher-order nonlinearities in a sample of cold cesium atoms obtained from a magneto-optical trap. Particularly, we demonstrate the storage of a third-, fifth-, and seventh-order nonlinear atom–light interaction into the coherences and populations of the Zeeman structure of the hyperfine cesium 6S1/2, F=3 ground state. Two writing beams create coherence and population gratings associated with high-order nonlinear processes, which can be selectively retrieved by a reading beam after a controllable storage time. Each kind of grating can store only specific orders of the nonlinear interaction, leading to special features in each signal. Applications of this nonlinear memory to herald multiphotons are discussed.

Optical memory based on quantized atomic center-of-mass motion.

We report a new type of optical memory using a pure two-level system of cesium atoms cooled by the magnetically assisted Sisyphus effect. The optical information of a probe field is stored in the coherence between quantized vibrational levels of the atoms in the potential wells of a 1-D optical lattice. The retrieved pulse shows Rabi oscillations with a frequency determined by the reading beam intensity and are qualitatively understood in terms of a simple theoretical model. The exploration of the external degrees of freedom of an atom may add another capability in the design of quantum-information protocols using light.

Direct evidence of visible surface plasmon excitation in ITO film coated on LiNbO3 slabs.

An iron-doped Y-cut lithium niobate (Fe:LN) slab was coated with indium-tin-oxide (ITO) thin films by magnetron sputtering. The electron confinement in a sub-nanometer region at ITO/LN interfaces is resulted from electric screening effect. Consequently, the local plasma frequency in the sub-nanometer metallic-like layer is shifted to the UV regime. This makes it possible to excite surface plasmon polaritons (SPPs) in the visible region with photorefractive phase gratings in the LN slab and to transport SPPs much energy-efficiently. Direct evidence of the excitation of SPPs was demonstrated by the presence of deep transmission spectral valleys in the transmission spectra and striking dark bands in the 2D diffraction patterns while using a white reading beam. Theoretical arguments and confirmation experiments are presented to elucidate all the related findings.

All-optical logical gates based on photoinduced molecules reorientation in amorphous polymer films

A type of all-optical logical gate based on two kinds of refractive index grating in azo-dye doped polymer film is studied in this paper. Using interference recording method with two 532[Formula: see text]nm laser beams, the transient refractive gratings can be formed in poly(methyl methacrylate) (PMMA) films containing azo-dye Disperse Red 13 (DR13). The characteristics of the transient gratings in films which are recorded by two 532[Formula: see text]nm laser beams with different polarization states are investigated by monitoring the first-order diffraction intensity of the readout He–Ne laser beam (632.8[Formula: see text]nm). It is found that the transient gratings in the polymeric films can be established and decayed in several seconds. Furthermore, we realize XOR and XNOR all-optical logical operation based on the relationship among the polarization states of the recording beams, the reading beam, and the diffraction beam.

Dependences of the Diffraction Efficiency of Photorefractive Holograms on the Sample Thickness and Orientation Angle in a (ī ī 0)-cut Bi12SiO20 Crystal

We present the results of experimental studies of the dependence of the diffraction efficiency of nonoblique transmission holograms formed in the sample of a (īī0)-cut photorefractive piezoelectric Bi12SiO20 crystal on the sample thickness and orientation angle of the grating vector at two fixed mutually orthogonal orientations of the linear polarization vector of the reading beam. It is shown that only if along with optical activity of the crystal, the electrooptic, inverse piezoelectric, and photoelastic effects are taken into account in the analytical diffraction model, it is possible to carry out satisfactory theoretical interpretation of the experimental data.

Formation Dynamics of Transmission Holograms in Lithium Niobate Crystals Doped by Copper Through High-Temperature Diffusion

The results of experimental realization of the technology of diffusion doping of X-cut congruent lithium niobate crystals by copper and the results of studying their photorefractive and photovoltaic properties are presented. The latter was done by using the Bragg diffraction of the reading beam with a wavelength of 655 nm on the dynamic transmission volume–phase holograms recorded by laser beams having a wavelength of 532 nm. It is shown that by their photogalvanic properties the created samples, which are 1.8 mm thick, are similar to the single crystals grown by the conventional method from melt containing copper monooxide as a supplement.

Suppression of the four-wave-mixing background noise in a quantum memory retrieval process by channel blocking

In a quantum memory scheme with the Raman process, the read process encounters noise from four-wave mixing (FWM), which can destroy the nonclassical properties of the generated quantum fields. Here we demonstrate experimentally that the noise from FWM can be greatly suppressed by simply reducing the FWM transition channels with a circularly polarized read beam while at the same time retaining relatively high retrieval efficiency.