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Volume 28, Issue 10
Displaying 1-14 of 14 articles from this issue
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Hiroshi NISHIHARA2000 Volume 28 Issue 10 Pages 643
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
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Nobuyuki IMOTO2000 Volume 28 Issue 10 Pages 644
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
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Masahiro MATSUOKA2000 Volume 28 Issue 10 Pages 645-649
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSEntangled states and their application in quantum optics are reviewed. First, the entangled states of the position and momentum in the EPR paradox and Bohm's spin version are reviewed. Then, various generation methods of entangled states in optics are described: polarization entanglement, frequency entanglement, and quadruture-phase entanglement. Finally, as their applications, fundamentals of quantum communication and teleportation are explained.View full abstractDownload PDF (865K) -
Masao KITANO, Keisaku YAMANE2000 Volume 28 Issue 10 Pages 650-655
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSThe quantum Zeno effect (QZE) is seemingly paradoxical in a sense that an inhibition of transition or a guidance of system can be realized without loss of probability amplitudes in spite of the use of non-unitary processes. But it is quite universal and has been found in various quantum systems as well as in classical wave systems. In this report we will present two examples of QZE in the field of optics . One is theoptical pumping scheme in which atomic spin motion can be controlled without photon absorption in the fast pumping limit. The other example is the light propagation through a series of offset-spliced fibers . Two propagation modes, wave and ray, are possible in optical fibers, and QZE is found to occur only in the former mode.View full abstractDownload PDF (927K) -
2000 Volume 28 Issue 10 Pages 655-655,662
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
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Katsuhiro NAKAMURA, Jun MA2000 Volume 28 Issue 10 Pages 656-662
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSThe frontier of quantum chaos emerging from mesoscopic quantum transport is reviewed. A singlestadium billiard and antidot superlattices with square and triangular arrays are chosen as prototype systems. The semiclassical theory plays an important role in interpreting the experimental issue. The area distribution of backscattering orbits and the bifurcation of periodic orbits are shown to affect the anomalousfluctuations in the magnetoresistivity. The optical realization of quantum chaos is also discussed.View full abstractDownload PDF (1217K) -
Kenju OTSUKA, Ryoji KAWAI2000 Volume 28 Issue 10 Pages 663-670
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSRecent topics and puzzling problems in nonlinear optical dynamics have been reviewed, focusingon physics and chaotic dynamics of laser-diode-pumped microchip solid-state lasers. Some attractive current issues in nonlinear dynamics of optical complex systems, including factorial dynamical pattern memory, chaos synchronization and chaotic itinerancy, have been discussed. Promising applications to ultrahigh-sensitivity selfmixing optical sensors and a green laser without green problem have been demonstrated.View full abstractDownload PDF (3903K) -
Shigeki TAKEUCHI2000 Volume 28 Issue 10 Pages 671-676
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSA quantum computation algorithm is demonstrated using single photons and linear optics. Quantum registers are realized by modes and polarization of photons, and the unitary transformations for them are implemented with linear optics. For each quantum computation, the answer to the Deutsch Jozsa problem for any 4 bit digit is given by a single-photon detection signal with a small error rate. The origin of the error is also studied and categorized according to the sources: systematic errors of quantum gates, phase relaxation, amplitude dumping, and misreadout. It is suspected that a demonstration of 11 qubits using linear optics anda single photon with less than a 20 % error rate is achievable by the technique used in the experiment. As a further objective, an idea to construct controlled-NOT gate using quantum phase gate (QPG) given by Chuang et. al., is introduced and experiments on the QPGs are also reviewed.View full abstractDownload PDF (1125K) -
Masato KOASHI2000 Volume 28 Issue 10 Pages 677-681
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSThe basic concept of quantum key distribution is reviewed. The security of quantum key distribution and nocloning (and related) theorems in the cases for various states are discussed. It is shown thatmany of the problems are related to what one can do and what one cannot do, under the restriction of not modifying the marginal density operator of a system. The security under the realistic situations is also briefly reviewed.View full abstractDownload PDF (1102K) -
Atsushi UCHIDA, Shigeru YOSHIMORI, Takeshi OGAWA, Masahiko SHINOZUKA, ...2000 Volume 28 Issue 10 Pages 682-689
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSWe have experimentally demonstrated synchronization of chaos generated in two Nd: YVO4 microchip lasers with master-slave coupling schemes. Synchronization was achieved when the optical frequencies of the master and the slave lasers are matched under injection locking. We conclude that the principle of chaos synchronization is regeneration of chaotic oscillations of the master laser in the slave laser cavitybecause the modulation parameters do not have to be matched between the two lasers.View full abstractDownload PDF (1394K) -
Katsuyuki KASAI, Noriaki ONODERA, Jiangrui GAO, Claude FABRE2000 Volume 28 Issue 10 Pages 690-694
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSWe have generated bright squeezed light and quantum-correlated twin photon beams by using a cw semimonolithic KTP Optical Parametric Oscillator (OPO), which exhibits a low oscillation threshold and is capable of oscillating even in the free-running (no external-feedback) condition. The pump beam reflected by the OPO, after a cascading nonlinearity process in the crystal, appears as bright squeezed light. The squeezing observed on the reflected pump beam from the semimonolithic OPO was 30% (inferred squeezing: 48%). The signal and idler beams generated by the optical parametric oscillator are highly quantum-correlated twin photon beams. Since the squeezing property of the intensity difference between the twin photonbeams is robust in the condition where the two fields are balanced, the squeezing can be observed even in the freerunning condition of the OPO. This intensity-difference squeezing observed between the twin photon beams from the free-running semimonolithic OPO was 70% (inferred squeezing: 87%).View full abstractDownload PDF (951K) -
Yuko FUKAMI, Kunio AWAZU2000 Volume 28 Issue 10 Pages 695-700
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSSuccessful removal of cholesterol ester accumulated in the arteriosclerotic region was achieved by the exposure of 5.75 μm-Free Electron Laser (FEL) which is absorbed by C=O stretching vibrations of ester. In this study, we discussed the wavelength selectivity of FEL exposure effect on cholesteryl oleate. As results, FT-IR spectroscopic measurements showed spectral broadening and sift to a longer wavelength at the absorption peak of 5.75 μm were observed. These results indicated that ester was dissociated, and that carboxylic acid was synthesized during the exposure. Further, we compared the exposure effect caused by FELs of 5.5-6.0 μm and 9.4 μm. The efficiency for a decrease of ester bonds was the highest with exposure of 5.75-5.79 μm-FEL, and ester bond was not dissociated by 9.4 μm-FEL. In conclusion, the FEL wavelength gives selectivity between the bonds which absorbs FEL photons and which aimed to remove.View full abstractDownload PDF (879K) -
Tamio HANAZAWA, Torao EGASHIRA2000 Volume 28 Issue 10 Pages 701-704
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSWe have attempted to clarify the mechanism of generating commutation spark by means of the images photographed with a high-speed camera. In the photographing system with the high-speed camera, we have contrived a new external laser trigger method that uses a laser beam as trigger signal for shutting of camera. In the external laser trigger method, we provide the motor fan with a 1-mm hole. When the laser beam passes through this hole, a trigger signal is generated, and this trigger signal performs shuttering of the high-speed camera via an optical detector and a pulse generator. The new external laser trigger method has enabled us to photograph spark of any commutator segment of the motor in high-speed rotation. Moreover, it has also become possible to photograph the process from generation to extinction of commutation spark, making us capable of analyzing the commutation spark from photographed images.View full abstractDownload PDF (740K) -
Satoshi IWAMOTO, Kazuo KURODA2000 Volume 28 Issue 10 Pages 705-711
Published: October 15, 2000
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSDownload PDF (1336K)
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