Abstract: A SIMOX wafer having a BOX layer with a thin film thickness is obtained without a reduction in productivity or deterioration in quality. In a method for manufacturing a SIMOX wafer comprising: a step of forming a first ion-implanted layer in a silicon wafer; a step of forming a second ion-implanted layer that is in an amorphous state; and a high-temperature heat treatment step of maintaining the wafer in an oxygen contained atmosphere at a temperature that is not lower than 1300° C. but less than a silicon melting point for 6 to 36 hours to change the first and the second ion-implanted layers into a BOX layer, a gas containing chlorine that is not less than 0.1 volume % but less than 1.0 volume % is mixed into an atmosphere during temperature elevation in the high-temperature heat treatment.

Abstract: A substrate surface serving as an SOI region and a substrate surface serving as a bulk region are made to form the same plane easily and highly accurately, a thickness of a buried oxide film is made uniform, and the buried oxide film is also prevented from being exposed on the substrate surface. After partially forming a mask oxide film (19) on a surface of a silicon substrate (12), an oxygen ions (16) are implanted into the surface of the substrate through this mask oxide film, and the substrate is further subjected to annealing treatment to form a buried oxide film (13) inside the substrate. Between the step of forming the mask oxide film and the step of implanting the oxygen ions, a recess portion (12c) with a predetermined depth deeper than a substrate surface (12b) serving as the bulk region where the mask oxide film has been formed is formed in a substrate surface (12a) serving as the SOI region where the mask oxide film is not formed.

Abstract: A process for manufacturing a silicon-on-insulator substrate comprising a single-crystal silicon substrate in which an oxide layer has been locally buried includes forming a step on the silicon substrate so that a region corresponding to the oxide layer has a greater surface height than other regions; then implanting oxygen ions in the silicon substrate so as to form the oxide layer.

Abstract: This method for manufacturing a SIMOX wafer includes: heating a silicon wafer to 300° C. or more and implanting oxygen ions so as to form a high oxygen concentration layer within the silicon wafer; subjecting the silicon wafer to a cooling to less than 300° C. and an implanting of oxygen ions so as to form an amorphous layer; and subjecting the silicon wafer to a heat-treating in a mixed gas atmosphere containing oxygen so as to form a buried oxide layer. In the forming of the buried oxide layer, a starting temperature is less than 1350° C. and a maximum temperature is 1350° C. or more. This SIMOX wafer is manufactured by the above method and includes a BOX layer and a SOI layer on the BOX layer. The BOX layer has a thickness of 1300 ? or more and a breakdown voltage of 7 MV/cm or more, and the surface of the SOI layer and the interface between the SOI layer and the BOX layer have a roughness over a 10-?m square area of 4 ? rms or less.

Abstract: In the method for manufacturing a SIMOX wafer, oxygen ions are implanted into a silicon wafer, then the silicon wafer is subjected to a prescribed heat treatment so as to form a buried oxide layer in the silicon wafer. The prescribed heat treatment includes: a step of ramping up a temperature of the silicon wafer in a low oxygen partial pressure gas atmosphere having an oxygen partial pressure ratio of less than 5%; either or both of a step of oxidizing the silicon wafer in a high oxygen partial pressure gas atmosphere having an oxygen partial pressure ratio of 5% or more and a step of annealing the silicon wafer in a low oxygen partial pressure gas atmosphere having an oxygen partial pressure ratio of less than 5%; and a step of ramping down the temperature of the silicon wafer in a low oxygen partial pressure gas atmosphere having an oxygen partial pressure ratio of less than 5%.

Abstract: A wafer (22) is placed on an upper surface of a holder body (23), and the holder body is inserted into a plurality of holder-aimed concave recesses (14) formed on supporters (12) accommodated in a heat treatment furnace such that the holder body is held horizontally. The holder body is formed into a disk shape free of recessed cut portions, and the holder body is formed with an upwardly projecting ring-like projection (24) extending in the circumferential direction of the holder body around the axis of the holder body. The wafer holder is constituted such that the wafer is placed on the holder body while contacting with the upper surface of the projection, and such that the outer diameter of the projection is formed to be in a range of 0.5D to 0.98D wherein D is the diameter of the wafer, so that the outer periphery of the wafer is kept from contacting with the projection. Occurrence of slips in the wafer is restricted by preventing warpage of the holder body upon fabricating the holder body.

Abstract: A hot isostatic pressing treatment is conducted for a single crystal body (11) in an atmosphere where the single crystal body (11) is stable, under a pressure of 0.2 to 304 MPa at a temperature which is 0.85 or more times the melting point in an absolute temperature unit of the single crystal body (11), for 5 minutes to 20 hours; and the single crystal body (11) is annealed. It is preferable that the atmosphere where the single crystal body (11) is stable is an inert gas atmosphere or an atmosphere containing vapor of a high vapor pressure element, and it is more preferable that the HIP treatment is conducted under a pressure of 10 to 200 MPa. Further, the single crystal body (11) may be an ingot of a silicon single crystal, a GaAs single crystal, an InP single crystal, a ZnS single crystal or a ZnSe single crystal, or a block or wafer obtained by slicing the ingot.

Abstract: An optical beam diameter reducer for reducing a beam diameter of an optical beam comprises a three-layer structure composed of a central core, a refractive index inclined layer formed outside the core which refractive index gradually decreases toward the outside in the radial direction and a cladding layer formed outside the refractive index inclined layer.

Abstract: It is an object of the present invention to provide a dampening volume control apparatus capable of shortening a period of time for adjusting a desired value of characteristics. A switch SW1 is a switch for switching the apparatus either in an automatic control mode or a manual control mode. A dampening volume of the dampening solution being stored in a manual dampening volume storing means 21 is varied by adjusting a switch SW21 and/or a switch 22. Revolution speed of a motor 25 is controlled by a controller 23 in accordance with the dampening volume thus varied. The switch SW1 is turned to the automatic control mode when the operator judges that quality of printing done on the printed papers is qualified to the criteria. The revolution speed of the motor 25 is controlled so as to make the dampening volume on the plate surface coincide with the volume corresponding to the desired value during the automatic control condition.

Abstract: A 1.3 .mu.m-band optical amplifier includes an optical amplifying fiber doped with Yb ion for emitting light in 1.02 .mu.m band by pumping of the 0.98 .mu.m band light and Pr ion for amplifying signal light by pumping of the 1.02 .mu.m band light. Both ends of the optical amplifying fiber are connected to optical fiber gratings for selectively reflecting 1.02 .mu.m band light via matching connecting members and tapered core optical fibers. The optical fiber gratings form a 1.02 .mu.m-band resonator. A Wavelength Division Multiplexing (WDM) optical coupler multiplexes the signal light and pumping light from an pumping laser and supplies the thus-multiplexed light to the optical fiber grating. The pumping laser comprises a laser device which causes laser oscillation at 0.98 .mu.m. A 1.5 .mu.m-band optical amplifier having a similar configuration is also disclosed.

Abstract: Oxygen ion is implanted into a silicon substrate to remain a silicon layer on a surface of the silicon substrate. In this state, a silicon oxide layer is formed under the silicon layer. Silicon oxide particles are formed and remained in the residual silicon layer. While maintaining this state, the silicon substrate is heated to a predetermined temperature not less than 1300.degree. C. Alternatively, the silicon substrate is heated at a high temperature-rise rate to 900-1100.degree. C., and thereafter is heated at a low temperature-rise rate to the temperature not less than 1300.degree. C. The silicon substrate is held at the predetermined temperature not less than 1300.degree. C. for a predetermined time, whereby crystallinity of the residual silicon layer is restored.

Abstract: Oxygen ion is implanted into a silicon substrate to remain a silicon layer on a surface of the silicon substrate. In this state, a silicon oxide layer is formed under the silicon layer. Silicon oxide particles are formed and remained in the residual silicon layer. While maintaining this state, the silicon substrate is heated to a predetermined temperature not less than 1300.degree. C. Alternatively, the silicon substrate is heated at a high temperature-rise rate to 900.degree.-1100.degree. C., and thereafter is heated at a low temperature-rise rate to the temperature not less than 1300.degree. C. The silicon substrate is held at the predetermined temperature not less than 1300.degree. C. for a predetermined time, whereby crystallinity of the residual silicon layer is restored.

Abstract: A high power laser transmitting fluoride glass fiber of an enhanced 2.94- .mu.m laser damage threshold value is disclosed, in which either of the core with a high refractive index and the cladding with a low refractive index is formed of fluoride glass which contains fluorine (F) as a component but has it substituted with 0 to 4.1 mol % of bromine (Br), chlorine (Cl), or bromine and chlorine. The optical fiber of the present invention may have its core formed of fluoride glass and its cladding formed of fluorine-contained resin, and the core glass has a composition that 70 to 80% of fluorine (F) is substituted with 0 to 4.1 mol % of bromine (Br), or chlorine (Cl), or bromine and chlorine.

Abstract: A polysilicon layer is formed on a surface of a silicon substrate after oxygen ions are implanted into the silicon substrate and an SiO.sub.2 film is formed in the silicon substrate at a position in a prescribed depth from the surface of silicon substrate. A heat treatment is performed to a silicon layer between the polysilicon layer and the SiO.sub.2 film, thereby providing an SOI layer with improved crystal quality.

Abstract: A polysilicon or amorphous Si layer is formed on a surface of a silicon substrate. Oxygen ions are implanted into the silicon substrate through the polysilicon layer, and an SiO.sub.2 film is formed in the silicon substrate at a position in a prescribed depth from the surface of silicon substrate. A heat treatment is performed to a silicon layer between the polysilicon layer and the SiO.sub.2 film, thereby providing an SOI layer with improved crystal quality.

Abstract: A high-output, single fundamental transverse mode solid state laser is disclosed which uses a semiconductor laser array as an excitation light source. The solid state laser comprises: a laser element which includes a core containing an element added as a laser medium, a cladding containing no such laser medium element, and reflecting mirrors coated over the cladding surface for repeatedly reflecting incident excitation light so that it may repeatedly pass through the core; an excitation light source formed by semi-conductor laser or light emitting diode array; means for guiding the excitation light from the excitation light source to one side of the laser element for incidence thereto; and a resonator for the oscillation of the solid state laser.

Abstract: A fusion splicing method for optical fibers in which optical fibers are fusion spliced in an inert gas atmosphere after water adsorbed on their surfaces is removed by decomposition in a plasma of an inert gas containing a halogen.

Abstract: A method and apparatus is disclosed which ensures highly accurate control of the core-cladding diameter, enabling the fabrication of a preform for the single mode fiber. Moreover, glass refining steps for dehydration, the removal of compound ions, the reduction of the absorption loss by transition metals, etc. and preform manufacturing steps are combined into a series of steps, and the entire manufacturing process can be mechanized and automatically controlled; therefore, the yield rate of product is high and the industrial-scale productivity is also excellent.

Abstract: In a fluoride glass optical fiber with extremely small transmission loss for infrared light having a core layer and a clad layer each consisting mainly of ZrF.sub.4 - BaF.sub.2 - LaF.sub.3 - AlF.sub.3, NaF and H.sub.f F.sub.4 are used as additives to obtain a desired refractive index difference between the core layer and the clad layer. The mixing ratio of the NaF to the H.sub.f F.sub.4 satisfies the realtions;.vertline.0.25 .DELTA.H.sub.f F.sub.4 -3.DELTA.NaF.vertline..ltoreq.5,where .DELTA.NaF is the difference between the amount (mol %) of the N.sub.a F to be added to the core layer and that to be added to the clad layer, and .DELTA.H.sub.f F.sub.4 to be added to the core layer and that to be added to the clad layer.

Abstract: A fluoride glass for infrared optical transmission fiber is purified for dehydration and deoxidation to reduce transmission loss by reacting melted fluoride glass with NF.sub.3 gas at temperature between 500.degree. C. and 800.degree. C. No scattering loss is increased by the present purification as decomposed product in the reaction does not precipitate.