Abstract: The present invention provides an optical transmission system that enables high-speed transmission of 40 Gb/s with low residual dispersion while maintaining the yield of a dispersion compensating fiber. In the present invention, the dispersion compensating fiber is connected to each span of an optical fiber for transmission. One set of an optical transmission path is formed by this optical fiber for transmission and the dispersion compensating fiber, and this one set of optical transmission path is connected in multiple stages and connected to a transmitter and a receiver. By setting the conditions of dispersion compensation in each span comparatively leniently, managing the residual dispersion of each transmission span, and suitably arranging each transmission span, an optical transmission system is composed in which adequate dispersion compensation is performed over the entire optical transmission path.

Abstract: A control apparatus and a control method of an on-vehicle dynamo-electric machine 1 are provided for efficiently controlling functions as a starter-motor and as a charging generator. In case that the dynamo-electric machine 1 acts as a charging generator, when a rotation speed of the dynamo-electric machine 1 is not higher than a predetermined value, a power is generated by applying a compensation current from and inverter to an armature coil 3 for phase control. On the other hand, when a rotation speed of the dynamo-electric machine 1 is not lower than a predetermined value, operation of the inverter is stopped. Thus, controlling a current applied to a field coil 4 by a field coil current control means 5 generates a predetermined target voltage.

Abstract: A dispersion compensating fiber, which has a negative dispersion slope with a large absolute value while maintaining the absolute value of the chromatic dispersion, and which has sufficient dispersion slope compensation properties even for the non-zero dispersion shifted optical fiber requiring a large RDS for dispersion compensation. In this dispersion compensating fiber, the radius of a ring core region is set in a range from 6.7 &mgr;m to 10.7 &mgr;m, the radius ratio of a depressed core region relative to a central core region is set in a range from 2.0 to 3.0, and the radius ratio of the ring core region relative to the depressed core region is set in a range from 1.3 to 2.0, the relative refractive index difference of the central core region relative to the cladding is set in a range from +1.00% to +1.80%, the relative refractive index difference of the depressed core region relative to the cladding is set in a range from −1.20% to −1.

Abstract: The present invention provides an optical transmission system that enables high-speed transmission of 40 Gb/s with low residual dispersion while maintaining the yield of a dispersion compensating fiber. In the present invention, the dispersion compensating fiber is connected to each span of an optical fiber for transmission. One set of an optical transmission path is formed by this optical fiber for transmission and the dispersion compensating fiber, and this one set of optical transmission path is connected in multiple stages and connected to a transmitter and a receiver. By setting the conditions of dispersion compensation in each span comparatively leniently, managing the residual dispersion of each transmission span, and suitably arranging each transmission span, an optical transmission system is composed in which adequate dispersion compensation is performed over the entire optical transmission path.

Abstract: This dispersion compensating optical fiber comprises an uncovered dispersion compensating optical fiber which contains a core and a cladding and a resin coating which is disposed around the uncovered dispersion compensating optical fiber and which has an adhesive property of 10 g/mm or less. Alternatively, the dispersion compensating optical fiber comprises an uncovered dispersion compensating optical fiber which contains a core and a cladding and a resin coating which is disposed around the uncovered dispersion compensating optical fiber, which has an adhesive property of 1 g/mm or less, and which includes a single or double coating layer and an outer coating layer formed on the surface of the single or double coating layer to have a thickness of 3 &mgr;m or more.

Abstract: A control apparatus and a control method of an on-vehicle dynamo-electric machine 1 are provided for efficiently controlling functions as a starter-motor and as a charging generator. In case that the dynamo-electric machine 1 acts as a charging generator, when a rotation speed of the dynamo-electric machine 1 is not higher than a predetermined value, a power is generated by applying a compensation current from and inverter to an armature coil 3 for phase control. On the other hand, when a rotation speed of the dynamo-electric machine 1 is not lower than a predetermined value, operation of the inverter is stopped. Thus, controlling a current applied to a field coil 4 by a field coil current control means 5 generates a predetermined target voltage.