Abstract: In a cryptographic key distribution system by the phase modulation using a single photon state or a faint LD light, there is required an interferometer independent on polarization and stabilized against thermal fluctuations in order to make a transmission distance longer. Cryptographic key distribution systems are generally low in cryptographic-key-generating efficiency, and an improvement in the efficiency is demanded. In the present invention, two interferometers are disposed within the receiver so as to require no phase modulator within the receiver, thereby achieving a polarization-independent receiver. The pulses are paired, and the signal is transmitted with the relative phase, and the interval of the paired pulses is sufficiently reduced to set the optical path within the interferometer in the receiver to be smaller, thereby achieving the interferometer stabilized against thermal fluctuations.

Abstract: A substrate processing apparatus of the present invention comprises: a processing chamber for storing and processing substrates stacked in multiple stages in horizontal posture; a processing gas supply unit for supplying two or more types of the processing gases to the inside of the processing chamber; an inactive gas supply unit for supplying an inactive gas to the inside of the processing chamber; and an exhaust unit for exhausting an atmosphere of the inside of the processing chamber, wherein the processing gas supply unit has at least two processing gas supply nozzles which extend running along an inner wall of the processing chamber in the stacking direction of the substrates and supply the processing gas to the inside of the processing chamber, and the inactive gas supply unit has a pair of inactive gas supply nozzles which are provided so as to extend running along the inner wall of the processing chamber in the stacking direction of the substrates and so as to sandwich at least one processing gas supp

Abstract: A substrate processing apparatus according to the present invention promotes supplying gases to spaces between adjacent substrates without reducing the number of substrates which can be collectively processed.

Abstract: A thin film is deposited on a substrate to be processed by continuously performing: forming an amorphous thin film composed of Ti, N, C, and H as principal components; oxidizing a surface of the thin film; removing C and H, which are impurities in the thin film, by a plasma treatment, and increasing the density of the thin film; and removing a TiO thin film from a surface of the thin film.

Abstract: In a quaternary phase modulator including two phase modulators disposed in parallel and a phase adjuster that adjusts a phase difference when the outputs of the two phase modulators are combined, there are provided a second light source that introduces light propagated in a backward direction, a first controller that controls the bias of the two phase modulators so that the intensity of the backward light is a minimum on the input side of the quaternary phase modulator, and a second controller that controls the bias of the phase adjuster so that a result monitored by a photodiode having a bandwidth not exceeding the bit rate on the output side of the quaternary phase modulator is a minimum, the first controller being implemented after the second controller is implemented.

Abstract: Provided is a cleaning method which can efficiently remove a film, such as a high dielectric constant oxide film, which is difficult to be etched by a fluorine-containing gas alone. As a cleaning method of a substrate processing apparatus which forms a desired film on a wafer by supplying a source gas, there is provided a cleaning method for removing a film attached to the inside of a processing chamber. The cleaning method includes: a step of supplying a halogen-containing gas into the processing chamber; and a step of supplying a fluorine-containing gas into the processing chamber, after starting the supply of the halogen-containing gas, wherein, in the step of supplying the fluorine-containing gas, the fluorine-containing gas is supplied while supplying the halogen-containing gas into the processing chamber.

Abstract: A data transmission system comprising a transmitter and a receiver. The transmitter comprises a phase encoder for partitioning consecutive bit data to be input in data in units of X bits; and converting a 2x value indicated by the data of X bits in unique association with an (N/2-1)Y value of a Y symbol, and for confining use of signal points, from among the signal points of N-ary phase, only to a signal point P1 (at a phase angle 0) and N/2-2 signal points P(2n+2) (where 1?n<N/2-2). The receiver comprises a phase decoder for notifying an error detection when a signal point other than a signal point that are permitted to be used is received, and performing an error correction by changing the signal point to a signal point which has a smaller hamming distance.

Abstract: A QPSK modulator comprising: two phase modulators implemented in parallel for outputting the light phase-modulated with an information signal; a phase shifter for shifting the phase of the light phase-modulated with the first phase modulator of the two phase modulators and for outputting the phase-shifted light; and a combiner for combining output light of the phase shifter and output light of the second phase modulator, in which a drive signal generated by multiplexing a signal of a first and second frequencies and the information signal is inputted into the first and second phase modulators, and in which the QPSK modulator feeds back a detected amount to a voltage applied to the phase shifter so that the phase shift amount may be ?/2, the detected amount of signals having the frequency of the difference between or the sum of the first and second frequency which are extracted from the modulated light.

Abstract: There is provided a substrate processing apparatus, comprising: a processing chamber that houses a plurality of substrates in a state of being stacked; a heating member that heats the substrate and an atmosphere in the processing chamber; a first gas supply member that supplies a source gas that thermally-decomposes; a second gas supply member that supplies oxidative gas; an exhaust member that exhausts the atmosphere in the processing chamber; and a controller that controls at least the first gas supply member, the second gas supply member, and the exhaust member.

Abstract: To improve a step coverage and a loading effect, without inviting a deterioration of throughput and an increase of cost, in a method for forming a thin film by alternately flowing a raw material and alcohol to a processing chamber.

Abstract: A magnetic material is provided that has an iron oxide phase whose principal phase is a crystal of a structure which has the same space group as ?-Fe2O3 crystal and in which Al is substituted for a portion of the Fe sites of the ?-Fe2O3 crystal. The molar ratio of Al to Fe in the iron oxide phase, when expressed as Al:Fe=x:(2?x), satisfies 0?x?1. The value of x is preferably in the range of 0.3 to 0.7. The average particle diameter of the powder determined from a TEM image is preferably 5 to 200 nm, more preferably 10 to 100 nm. The magnetic material has very high practical value because it enables the extremely high coercive force Hc of the ?-Fe2O3 crystal to be regulated to a level enabling utilization in magnetic recording medium and various other applications. The magnetic powder can be produced by a method combining the reverse micelle method and the sol-gel method.

Abstract: An optical transmission system accomplishes optical transmission over a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission over a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.

Abstract: A magnetic powder for magnetic recording medium comprises acicular particles constituted primarily of Fe, wherein the powder contains Co in an amount such that the Co/Fe ratio is 50 at. % or less and the Co is contained in a manner such that the surface portion has a higher concentration than the core portion of the particles, and upon subjecting the magnetic powder for magnetic recording medium to TG measurement, the powder exhibits at least two oxidation starting points: a low-temperature side oxidation starting point and a high-temperature side oxidation starting point. The magnetic powder achieves improved resistance to oxidation without sacrificing magnetic characteristics.

Abstract: An optical transmission system accomplishes optical transmission over a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission over a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.

Abstract: An optical transmission system accomplishes optical transmission over a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission over a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.

Abstract: In a cryptographic key distribution system by the phase modulation using a single photon state or a faint LD light, there is required an interferometer independent on polarization and stabilized against thermal fluctuations in order to make a transmission distance longer. Cryptographic key distribution systems are generally low in cryptographic-key-generating efficiency, and an improvement in the efficiency is demanded. In the present invention, two interferometers are disposed within the receiver so as to require no phase modulator within the receiver, thereby achieving a polarization-independent receiver. The pulses are paired, and the signal is transmitted with the relative phase, and the interval of the paired pulses is sufficiently reduced to set the optical path within the interferometer in the receiver to be smaller, thereby achieving the interferometer stabilized against thermal fluctuations.

Abstract: An optical wiring substrate provides a slab optical waveguide having a refractive index different from a refractive index of other surrounding portions and a planar convex lens being provided continuously to a tip portion of an optical path of an optical wave guide including a core and cladding and formed on a substrate. The optical path of light passing through the planar convex lens is converted approximately by 90° with a mirror. The light reflected with the mirror is made as parallel light rays by use of a cylindrical lens.

Abstract: It was difficult to detect a wavelength error. Further, a wavelength error of an optical add signal is accompanied by a calculation error of the number of wavelengths of a wavelength division multiplexing signal, which causes a set value of an optical signal level to become abnormal, resulting in the degradation of the optical signal. According to the present invention, part of an inputted optical add signal 118 is reflected by a mirror 117, and is thereby inputted into an optical wavelength multiplexer 105 in the reverse direction so that the optical add signal is returned to paths 115-1 through 115-16 corresponding to wavelengths ?1 through ?16. If the returned optical add signal is an optical add signal having a correct wavelength (in FIG. 1, ?16), the optical signal enters its corresponding backward direction optical detector 113-16. Accordingly, it is possible to check whether or not a wavelength of the optical add signal is correct.

Abstract: A problem to be solved in an optical communication system for carrying out bidirectional transmission between communication nodes by wavelength-division-multiplexed optical signals is that a plurality of optical add-drop multiplexers installed in the communication nodes are required for each transmission direction, and therefore, the communication cost is increased. An optical circulator or an optical coupler is arranged at an input/output port of the optical add-drop multiplexer and the wavelength-division-multiplexed optical signals are assembled for each transmission direction, whereby optical signals transmitted bidirectionally can be handled by one optical add-drop multiplexer.

Abstract: An optical coupling structure useful in optical switching devices is described. The optical coupling structure includes a core layer for guiding a light beam exiting a core layer of an optical fiber into a slab waveguide layer. The core layer of the optical coupling structure avoids a power loss of a light beam and establishes an adiabatic coupling. The core layer of the optical coupling structure may have a tapered surface.