Abstract: A polypropylene composition made from or containing a first polymer consisting of component (1) made from or containing a propylene homopolymer having an MFR of 80 to 300 and containing 97.5% by weight or more of xylene insolubles (XI), wherein XI of the propylene homopolymer has a Mw/Mn of 4 to 10; and component (2) made from or containing an ethylene/propylene copolymer containing 35 to 50% by weight of an ethylene-derived unit; wherein the polypropylene composition has the following characteristics: 1) the relative proportions of component (2)/[component (1) and component (2)] is more than 30% by weight and not more than 50% by weight, 2) the intrinsic viscosity of xylene solubles (XSIV) of the first polymer is in the range of 1.5 to 4.0 dl/g, and 3) the MFR of the first polymer is in the range of 20 to 100 g/10 min.

Abstract: A polypropylene composition made from or containing a polymer made from or containing: (i) component (1) made from or containing a propylene homopolymer having MFR of 100 to 300 (at a temperature of 230° C. under a load of 2.16 k(g) and containing more than 97.5% by weight of xylene insolubles (XI), wherein XI has a Mw/Mn of 4 to 10; (ii) component (2) made from or containing an ethylene/propylene copolymer containing 15 to 50% by weight of an ethylene-derived unit; wherein 1) relative proportions of component (1) and component (2) are, respectively, not less than 50 parts by weight but less than 70 pbw and more than 30 pbw but not more than 50 pbw, 2) intrinsic viscosity of xylene solubles (XSIV) of the polymer is in the range of 1.5 to 4.0 dl/g, 3) MFR of the polymer is in the range of 20 to 100 g/10 min.

Abstract: A polypropylene-based resin composition contains: a component (A1) being a propylene homopolymer or a copolymer of propylene and a 30 wt % or less ?-olefin having 2 or 4 to 8 carbon atoms, having a intrinsic viscosity of more than 20 dl/g, as measured in a tetralin solvent at 135° C.; and a component (A2) being a polymer selected from the group consisting of (A2-1) a propylene homopolymer, (A2-2) a random copolymer of propylene and an ?-olefin having 2 or 4 to 8 carbon atoms, (A2-3) a block copolymer of propylene and an ?-olefin having 2 or 4 to 8 carbon atoms, and a combination of the (A2-1), (A2-2), and (A2-3). The resin composition has a content of the component (A1) of 0.1 to 10 wt % and a content of the component (A2) of 99.9 to 90 wt % based on the total amount of the component (A1) and the component (A2). The component (A2) has a melt flow rate (MFR) (230° C., load: 2.16 kg) of 1 to 500 g/10 min.

Abstract: A polypropylene composition made from or containing a polymer made from or containing: (i) component (1) made from or containing a propylene homopolymer having MFR of 100 to 300 (at a temperature of 230° C. under a load of 2.16 kg) and containing more than 97.5% by weight of xylene insolubles (XI), wherein XI has a Mw/Mn of 4 to 10; (ii) component (2) made from or containing an ethylene/propylene copolymer containing 15 to 50% by weight of an ethylene-derived unit; wherein 1) relative proportions of component (1) and component (2) are, respectively, not less than 50 parts by weight but less than 70 pbw and more than 30 pbw but not more than 50 pbw, 2) intrinsic viscosity of xylene solubles (XSIV) of the polymer is in the range of 1.5 to 4.0 dl/g, 3) MFR of the polymer is in the range of 20 to 100 g/10 min.

Abstract: There is provided an optical rotation measurement apparatus and a measuring system which are user-friendly, capable of measuring glucose concentration in drawn blood and living bodies with high accuracy in real time such that it is available for use at an actual medical site without depending on a reagent, and capable of measuring glucose concentration in a living body noninvasively with high accuracy, a new polarized light converting optical system that can be used for the measuring system, and an optical rotation measurement method using the optical system.

Abstract: There is provided an optical rotation measurement apparatus and a measuring system which are user-friendly, capable of measuring glucose concentration in drawn blood and living bodies with high accuracy in real time such that it is available for use at an actual medical site without depending on a reagent, and capable of measuring glucose concentration in a living body noninvasively with high accuracy, a new polarized light converting optical system that can be used for the measuring system, and an optical rotation measurement method using the optical system.

Abstract: A small-size optical rotation measuring device for detecting an organism, a tissue, blood, or molecules having rotatory power and determining the content thereof with high accuracy and an optical rotation measuring method for detecting an organism, a tissue, blood, or molecules having rotatory power and determining the content thereof with high accuracy. A nonreciprocal optical system is disposed in a loop optical path of a ring optical interferometer, and thereby light beams of circularly polarized modes orthogonal to each other are propagated in opposite directions through a sample to be measured. The wavelength of the light beams from a light source is in a wavelength region where the loss by the nonreciprocal optical element is low. A signal processing technique for phase-modulation optical fiber gyro having the highest resolution among ring interferometers is applied.

Abstract: A phase modulated light is propagated through an optical fiber sensing loop, from which a propagated light is obtained. The propagated light is converted to an electric signal, from which a fundamental wave component and even number harmonic wave components of a phase modulating signal for the phase modulated signal are detected. In accordance with the changes of the fundamental and even number harmonic wave components, fault is detected. On the other hand, the electric signal may be integrated to provide an integrated signal. In accordance with the comparison between the integrated signal and a fault reference voltage, the fault may be detected.

Abstract: The orientation of the rotating direction of an optical fiber in an optical fiber array takes the positional axial displacement into consideration. In a method of aligning the orientation of optical fibers, or the axial displacement in an optical fiber array having a plurality of optical fibers, and an optical fiber holding member, an enlarged image of the optical fiber is obtained for each of the optical fibers using an image pick-up means. Then, a distribution of the characterized image corresponding to the positions in the radial direction of the image of the optical fiber are obtained from the enlarged image. From the distribution of the characterized image, the orientation of the rotational direction to the center of the optical fiber, or the positional axial displacement of the core center, is measured.

Abstract: A photodetector generates an electric signal by receiving a light signal which is obtained by coupling lights having propagated through an optical fiber sensing loop in clock-wise and counter clock-wise directions, and modulated in a phase modulator. The electric signal is detected in a synchronous detection circuit to generate a fundamental wave component of the phase modulation signal, a duplicate harmonic wave component, a quadruple harmonic wave component, and an orthogonal component which is obtained in accordance with a phase shift of the quadruple harmonic wave component by one quarter period.

Abstract: A signal processing circuit of an optical fiber gyro comprises a memory for storing data measured in the signal processing circuit in accordance with angular velocities applied to an optical fiber sensing loop at preparatory stage, and the applied angular velocities. In operation, the memory is accessed in accordance with data obtained in the signal processing circuit at an operation stage, so that an angular velocity is read from the memory without complicated calculation.

Abstract: A method of producing an elliptic core type polarization-maintaining optical fiber comprises the steps of providing a glass rod comprising a cladding glass layer around the periphery of a core glass layer, the cladding glass layer having a softening point higher than the softening point of the core glass layer, removing two side surface portions of the glass rod by machining along the axial direction of the glass rod to form a machined rod noncircular in cross section, outside depositing fine silica glass particles on the periphery of the machined rod, followed by sintering to provide a support glass layer having a softening point higher than the softening point of the cladding glass layer, and drawing the thus obtained glass rod body as an optical fiber preform. Since the portion for constituting the core of the optical fiber is formed by machining, the core is permitted to have a high ellipticity.

Abstract: In an optical fiber gyro for detecting a rotation angular velocity by Sagnac phase difference of light signals propagated through an optical fiber sensing loop, no polarizer is used, and a light source having a difference in attenuation or amplification factor between two orthogonally polarized lights is used. Alternatively, a light source is optically coupled to an optical coupler for supplying two divided light signals to the sensing loop and receiving the two light signals propagated through sensing loop by an optical fiber of a predetermined length which is set to meet a relation in which a distance difference determined by the predetermined length and a phase difference of two orthogonally polarized lights propagated through the optical fiber is greater than an interference distance of the light source.

Abstract: The light emitted from a laser diode is divided into two lights and the divided lights are introduced into a sensing loop such that the lights propagate through the sensing loop clockwise and counterclockwise. These lights are combined by a light receiving device and then a signal processing circuit calculates an angular velocity .OMEGA.'. The temperature near the laser diode is detected to obtain a correction value Kt, a current supplied to the laser diode is detected to obtain a correction value Ki and a corrected angular velocity .OMEGA. is obtained by calculating the product of the angular velocity with the correction values Ki and Kt, i.e., .OMEGA.=.OMEGA.'*Ki*Kt.

Abstract: An interference sensor passes radiation from a source and a polariser to a loop of optical fiber so that radiation beams circulate in opposite directions around the loop and interfere. The loop contains an optical phase modulator which imposes an optical modulator on the radiation beams circulating on the loop. A converter detects the interfering and modulated beams and generates an interference signal which is then processed by an analyser. The interference in the loop is dependent on rotation of the loop and therefore analysis of the interference signal permits that rotation to be measured. In the present invention, the interference signal is (i) sampled at a frequency different from that of the optical modulation, or (ii) electronically modulated in the analyser at a frequency different from that of the optical modulation, or (iii) optically modulated in the loop at a second optical modulation frequency. The analysis in the analyser may be in the frequency domain (i.e.

Abstract: The fiber-optic rotation sensor comprises a sensing loop using an optical fiber which essentially performs a single polarization when bent, both end portions of the sensing loop being disposed with the principal axes of polarization thereof orthogonal to each other and the end portions being joined by an evanescent wave coupling to form a ring interferometer, a device for introducing to an input end of the interferometer a linearly polarized light at a bearing of 45.degree. relative to the principal axis of polarization of the interferometer, and a retardation measuring system provided at an output end of the interferometer for picking up an electrical output proportional to a rotational angular velocity applied to the interferometer. When the linearly-polarized light is introduced to the input end of the coupling portion of the ring interferometer at a bearing of 45.degree.

Abstract: In an optical fiber gyroscope, the sensitivity thereof is optimized with a phase bias afforded by utilizing the phase characteristics of an optical branching/coupling unit. Further, the fluctuation of the intensity of a light source and the error and secular change of the phase characteristics of the optical branching/coupling unit are compensated by an electronic circuit. Moreover, an optical fiber loop is located in a heat insulation casing so as not to be affected by an ambient temperature change, thereby to prevent the drift of the optical fiber gyroscope attributed to an temperature change. Thus, the optical fiber gyroscope of high measurement accuracy is provided.

Abstract: Two opposite portions of the surface of a core rod whose section is circular are removed by machining in the longitudinal direction thereof, so that the section of the core rod is transformed into a non-circular shape. On the surface of the thusly shaped non-circular core rod, glass particulates are accumulated, and then the glass particulates accumulated on the core rod are sintered to create a preform. Then, the preform is heated and drawn, so that a polarization-maintaining optical fiber of non-circular section is obtained.

Abstract: A rotary joint for polarization plane maintaining optical fibers which can couple two polarization plane maintaining optical fibers to each other while maintaining the polarization plane maintaining property. The rotary joint comprises a rotary member, a fixed member, two optical fiber collimators and a 1/2 wavelength plate for coupling a polarization plane maintaining optical fiber connected to the rotary member with another polarization plane maintaining optical fiber connected to the fixed member, and gears for rotating the 1/2 wavelength plate at a speed equal to one half the rotational speed of the polarization plane maintaining optical fiber on the rotary member side.

Abstract: A polarized wave preserving fiber has a core at its center, cladding, an oval jacket, and a support member in order to improve transmitting property of the polarized single mode by adjusting the refractive index distribution and the ellipticity of the oval jacket.