Abstract: A substrate processing apparatus includes a processing chamber; process areas each of which supplies a reaction gas; a turntable that rotates to cause a substrate to pass through the process areas; a gas nozzle provided in one of the process areas; a separating area that supplies a separation gas to separate atmospheres of the process areas; and a cover part configured to cover the gas nozzle and cause the reaction gas supplied from the gas nozzle to remain around the gas nozzle. The cover part includes an upstream side wall, a downstream side wall, and an upper wall. The cover part also includes a guide surface configured to guide the separation gas to flow over a lower part of the upstream side wall to a space above the upper wall. The distance between the gas nozzle and the upstream side wall is greater than or equal to 8 mm.

Abstract: A substrate processing apparatus includes a process chamber; a turntable rotatably provided in the process chamber for mounting a substrate on one surface of the turntable and including a substrate mounting portion at which the substrate is to be mounted and a table body which is an other portion of the turntable, the substrate mounting portion being configured to have a heat capacity smaller than that the table body; and a heater that heats the substrate from an opposite surface side of the turntable.

Abstract: An ON-OFF traffic characteristic can be analyzed in real time from a measurement value without requiring detailed data analysis which is performed using measurement values accumulated for a predetermined time period through a high-performance measurement apparatus. A packet length and a packet transfer time interval of a communication traffic are first measured, and a data transfer rate variance indicator is computed based on a relative entropy value between the measured packet transfer time interval and a packet transfer time interval in case of transferring at a constant transfer rate. A predetermined traffic characteristic value is at least approximately computed using the computed data transfer rate variance indicator.

Abstract: A data transfer rate variance indicator having a small amount of calculation for each one packet and a small necessary amount of buffer (memory size), and representing a value suitable for traffic quality evaluation is to be used. Therefore, a packet transfer time interval is measured, and a data transfer rate variance indicator which is obtained based on a relative entropy value between the measured packet transfer time interval and a packet transfer time interval in a case where transfer is performed at a constant transfer rate is used for calculation.

Abstract: An ON-OFF traffic characteristic can be analyzed in real time from a measurement value without requiring detailed data analysis which is performed using measurement values accumulated for a predetermined time period through a high-performance measurement apparatus. A packet length and a packet transfer time interval of a communication traffic are first measured, and a data transfer rate variance indicator is computed based on a relative entropy value between the measured packet transfer time interval and a packet transfer time interval in case of transferring at a constant transfer rate. A predetermined traffic characteristic value is at least approximately computed using the computed data transfer rate variance indicator.

Abstract: A data transfer rate variance indicator having a small amount of calculation for each one packet and a small necessary amount of buffer (memory size), and representing a value suitable for traffic quality evaluation is to be used. Therefore, a packet transfer time interval is measured, and a data transfer rate variance indicator which is obtained based on a relative entropy value between the measured packet transfer time interval and a packet transfer time interval in a case where transfer is performed at a constant transfer rate is used for calculation.

Abstract: Upon controlling the operation of a shaper for performing the shaping of data communication that establishes a flow between data communication apparatuses via a network, the data communication apparatus identifies the flow and designates whether or not the shaping of the identified flow is performed, and the shaping on the unit basis of the flow is performed in accordance with the designation.

Abstract: A concentric multi-tubular burner for synthesizing glass particles having a center port group constituted by a combination of jet ports of raw material gas, combustible gas and oxygen gas, wherein an outer wall of the oxygen gas jet port in the center port group protrudes more toward a burner head than an inner wall of the oxygen gas jet port. The flow rate of oxygen gas jetted from the oxygen gas jet port of the center port group is controlled to be in a proper range.

Abstract: Stress exerted on an inner or outer circumferential side of a glass tube 6 is controlled when a glass material 3 is heated and softened by a heating element 41 provided around the glass material 3 and a piercing plug 31 is relatively pressed into a softened region of the glass material 3 to thereby form the glass material 3 into the glass tube 6 gradually. For example, the control of the stress can be carried out by controlling an internal or external pressure of the glass tube 6. As a result, the deformation of the glass tube 6 just after piercing is prevented so that the glass tube 6 can be obtained with high quality. It is also possible to solve the problem that cracks may occur easily at the time of reheating because of residual stress distribution after cooling.

Abstract: A dehydration and consolidation furnace and a dehydration and consolidation method in which gas in a chamber does not leak to a furnace body room and gas in a furnace body room does not leak into a chamber is provided. A furnace of one embodiment of this invention has first muffle tube 3 and second muffle tube 4. The second muffle tube 4 is arranged coaxially around the first muffle tube 3. An optical fiber preform is arranged in this furnace. During the dehydration and consolidation process the pressure of the intermediate room 10 is set lower than a pressure inside the first muffle tube and outside the second muffle tube, and a gas supply and exhaust of the intermediate room 10 are performed independent of the gas supply and exhaust of the first muffle tube and a furnace body room.

Abstract: Stress exerted on an inner or outer circumferential side of a glass tube 6 is controlled when a glass material 3 is heated and softened by a heating element 41 provided around the glass material 3 and a piercing plug 31 is relatively pressed into a softened region of the glass material 3 to thereby form the glass material 3 into the glass tube 6 gradually. For example, the control of the stress can be carried out by controlling an internal or external pressure of the glass tube 6. As a result, the deformation of the glass tube 6 just after piercing is prevented so that the glass tube 6 can be obtained with high quality. It is also possible to solve the problem that cracks may occur easily at the time of reheating because of residual stress distribution after cooling.

Abstract: A process for producing fluorine-containing glass. An SiO2 soot is synthesized by hydrolyzing SiCl4. The soot is heated in a chlorine-compound-free atmosphere containing a fluorine compound gas to form a fluorine-containing silica glass. The glass contains not more than 10 ppm OH group, not more than 10 ppm Cl, and not less than 1,000 ppm F. The concentration ratio of F/Cl is 10,000 or more.

Abstract: A concentric multi-tubular burner for synthesizing glass particles having a center port group constituted by a combination of jet ports of raw material gas, combustible gas and oxygen gas, wherein an outer wall of the oxygen gas jet port in the center port group protrudes more toward a burner head than an inner wall of the oxygen gas jet port. The flow rate of oxygen gas jetted from the oxygen gas jet port of the center port group is controlled to be in a proper range.

Abstract: An optical fiber grating device 1 is a device in which a long period grating 14 is formed in a core region 11 of an optical fiber 10 consisting of the core region 11 having a refractive index n1 and an outside diameter 2a, a first cladding region 12 surrounding the core region 11 and having a refractive index n2 and an outside diameter 2b, and a second cladding region 13 surrounding the first cladding region 12 and having a refractive index n3 and an outside diameter 2c. There is a magnitude relation of n1>n2>n3 among the refractive index n1 of the core region 11, the refractive index n2 of the first cladding region 12, and the refractive index n3 of the second cladding region 13, a relative refractive index difference &Dgr;n2 of the first cladding region 12 to the second cladding region 13 is not less than 0.5%, and a thickness (c−b) of the second cladding region 13 with respect to a transmission loss peak wavelength &lgr; is in a range of not less than &lgr; nor more than 10&lgr;.

Abstract: The present invention relates to a method of making a glass tube. In the method, a diameter expanding member is inserted through a hole in a tubular glass blank so as to expand the diameter of the hole while the temperature of the glass blank is controlled to be more than or equal to the softening point. The tubular glass blank may be a purchased product or a self-made product. In the above-mentioned method of making a glass tube, the diameter of the hole in the glass blank may be expanded while at least the rear end of the diameter expanding member is supported. The diameter of the hole in the glass blank may be expanded while both ends of the diameter-expanding member are supported. The present invention also relates to an apparatus for manufacturing a glass tube.

Abstract: A concentric multi-tubular burner for synthesizing glass particles having a center port group constituted by a combination of jet ports of raw material gas, combustible gas and oxygen gas, wherein an outer wall of the oxygen gas jet port in the center port group protrudes more toward a burner head than an inner wall of the oxygen gas jet port. The flow rate of oxygen gas jetted from the oxygen gas jet port of the center port group is controlled to be in a proper range.

Abstract: In an optical waveguide grating in an optical fiber having a cladding region around a core region, a periodic refractive index distribution is existed in a predetermined area of the core region along the optical axis. The core region has a composition of GeO2—P2O5—SiO2 based glass, for example, whereas the cladding region is made of SiO2, and the co-doping ratio in the core region is adjusted, so as to lower the temperature dependence of characteristics. The doping amount of P2O5 in the core region is preferably {fraction (1/15)} to 1 times, more preferably 0.6 to 1 times that of GeO2.

Abstract: An optical fiber grating device 1 is a device in which a long period grating 14 is formed in a core region 11 of an optical fiber 10 consisting of the core region 11 having a refractive index n1 and an outside diameter 2a, a first cladding region 12 surrounding the core region 11 and having a refractive index n2 and an outside diameter 2b, and a second cladding region 13 surrounding the first cladding region 12 and having a refractive index n3 and an outside diameter 2c. There is a magnitude relation of n1>n2>n3 among the refractive index n1 of the core region 11, the refractive index n2 of the first cladding region 12, and the refractive index n3 of the second cladding region 13, a relative refractive index difference &Dgr;n2 of the first cladding region 12 to the second cladding region 13 is not less than 0.5%, and a thickness (c−b) of the second cladding region 13 with respect to a transmission loss peak wavelength &lgr; is in a range of not less than &lgr; nor more than 10&lgr;.

Abstract: Fluorine-containing glass which comprises silica and contains, in said silica, not more than 10 ppm of OH group, not more than 10 ppm of Cl and not less than 1000 ppm of F, said fluorine-containing glass having a concentration ratio of F/Cl of 100 or more. Also disclosed is fluorine-containing glass which contains not more than 10 ppm of OH group, not more than 10 ppm of Cl and not less than 1000 ppm of F, and has a concentration ratio of F/Cl of 1000 or more.

Abstract: The present invention relates to a long-period grating device which eliminates only a desirable wavelength of core-mode light in a wavelength band in use from 1525 nm to 1610 nm. The long-period grating device according to the present invention comprises an optical fiber provided with a core region and a cladding region, whereas a long-period grating whose refractive index changes with a period &Lgr; in the advancing direction of light is provided in the core region, wherein the period &Lgr; is set such that the absolute value of a loss peak due to mode coupling concerning a refractive index modulation component with a period &Lgr;/(2n+1) (n=1, 2, 3, 4) is 0.2 dB or less in the wavelength band in use.