Abstract: An optical fiber whose chromatic dispersions have an opposite sign relative to those of the 1380 nm zero-dispersion fiber at all of the wavelengths in the range of 1450 nm to 1620 nm is provided. This optical fiber has negative chromatic dispersions at all of the wavelengths in this range and the values of which are −7 ps·nm−1·km−1 or more but −1 ps·nm−1·km−1 or less at a wavelength of 1450 nm, −12 ps·nm−1·km−1 or more but −5 ps·nm−1·km−1 or less at a wavelength of 1550 nm and −17 ps·nm−1·km−1 or more but −6 ps·nm−1·km−1 or less at a wavelength of 1620 nm. This optical fiber can compensate the dispersions of 1380 nm zero-dispersion fiber over the entire wavelength in this range.

Abstract: The present invention relates to an optical fiber which enables favorable optical communications in 1.3-&mgr;m and 1.55-&mgr;m wavelength bands, and an optical transmission system including the same. The optical fiber according to the present invention has only one zero-dispersion wavelength within a wavelength range of 1.20 &mgr;m to 1.60 &mgr;m, the zero-dispersion wavelength existing within a wavelength range of 1.37 &mgr;m to 1.50 &mgr;m, and has a positive dispersion slope at the zero-dispersion wavelength, thereby enabling favorable optical communications utilizing each signal light in the 1.3- &mgr;m and 1.55- &mgr;m wavelength bands sandwiching the zero-dispersion wavelength.

Abstract: In a dielectric transmission line device and a radio device using a dielectric transmission line device, an output matching circuit is constructed in a simplified fashion and an output signal of a frequency multiplier is output via a dielectric transmission line. The frequency multiplier is constructed in a small form in the dielectric transmission line device so as to obtain a dielectric transmission line device with a small total size and also obtain a small-sized high-efficiency radio device using such a dielectric transmission line device as a transmission line for transmitting a transmission signal. An input matching circuit is disposed between an input terminal and an FET for generating a harmonic. An open-ended transmission line is also provided which is coupled with an electromagnetic field of a dielectric transmission line in the form of a dielectric strip.

Abstract: An optical fiber that can sufficiently suppress the generation of four-wave mixing and that can widen the bandwidth of wavelength of signal light. The optical fiber of the present invention has (a) a chromatic dispersion whose absolute value is not less than 8 ps·nm−1·km−1 and not more than 15 ps·nm−1·km−1 at a wavelength of 1.55 &mgr;m and (b) a dispersion slope whose absolute value is not more than 0.05 ps·nm−2·km−1 at a wavelength of 1.55 &mgr;m. It is more desirable that the optical fiber have (a) a chromatic dispersion whose absolute value is not less than 8 ps·nm−1·km−1 and not more than 12 ps·nm−1·km−1 at a wavelength of 1.55 &mgr;m, (b) a dispersion slope whose absolute value is not more than 0.03 ps·nm−2·km−1 at a wavelength of 1.

Abstract: The present invention relates to a dispersion-shifted optical fiber suitable for an optical transmission line having an optical fiber amplifier with a wider amplification band. In particular, the dispersion-shifted optical fiber according to the present invention has a zero-dispersion wavelength of 1610 nm or more but 1750 nm or less, and a cutoff wavelength of 1.1 &mgr;m or more at a length of 2 m in order to suppress the bending loss to a practically permissible range, and has, with respect to light having a wavelength of 1550 nm, an effective area of 45 &mgr;m2 or more and a dispersion slope of 0.15 ps/nm2/km or less in order to suppress the occurrence of nonlinear phenomena.

Abstract: The present invention relates to a dispersion-shifted optical fiber comprising a structure for reducing optical loss and restraining nonlinear phenomena from occurring. In order to restrain the nonlinear phenomena from occurring, this dispersion-shifted optical fiber has an effective area of 70 &mgr;m2 or more with respect to light whose center wavelength falls within the range of 1500 to 1600 nm, and the peak position where optical power of the light in a fundamental mode is maximized is radially shifted from a center of a core region by a predetermined distance. Also, in this dispersion-shifted optical fiber, optical power at a position radially separated from the peak position by a distance which is five times the center wavelength of the light becomes {fraction (1/100)} or less of the optical power at the peak position. As a consequence of this structure, bending loss can effectively be reduced.

Abstract: Electrodes are formed on respective two main surfaces of a dielectric sheet wherein each electrode has an opening formed at a location corresponding to the location of the opening formed in the other electrode. The part defined by the openings serves as a dielectric resonator. Coupling lines are formed directly in the electrode opening. Transmission lines are formed on a circuit board. The coupling lines and the corresponding transmission lines are connected to each other via bonding wires. This structure makes it possible to minimize the external Q of a resonant circuit using the dielectric resonator. If an oscillator is produced using this resonant circuit, it is possible to achieve a large frequency modulation with and large output.

Abstract: A radio-frequency radiation source comprises electrodes containing opposing electrodeless parts formed on both sides of a dielectric plate in which the electrodeless parts are made to function as a dielectric resonator, a slit formed in the electrodeless part, and a switching element mounted over the slit. Further, a transmission line coupled to the dielectric resonator is provided. As constructed this way, the resonance frequency of the resonator is switched by turn-on and turn-off of the switching element. When the resonator resonates with the frequency of a signal propagated through the transmission line, the energy of the electromagnetic field is radiated to the outside through a slot.

Abstract: The present invention provides a dispersion-shifted fiber which can effectively restrain nonlinear optical effects from occurring and is suitable for long-haul transmission. As characteristics at a wavelength of 1,550 nm, this dispersion-shifted fiber has a dispersion whose absolute value is from 1.0 to 4.5 ps/nm/km, an effective core cross-sectional area of at least 70 &mgr;m2, a cutoff wavelength of at least 1,300 nm at a fiber length of 2 m, and a dispersion slope of 0.05 to 0.09 ps/nm2/km. Also, in this dispersion-shifted fiber, the position where the optical power distribution in the fundamental mode of the signal light is maximized is radially separated from the center of the core region by a predetermined distance, and, when the optical power in the fundamental mode of signal light at the center of core region is P0, and the maximum value of the optical power distribution in the fundamental mode is P1, the maximum value P1 is greater than the value of 1.

Abstract: The present invention aims at providing a dispersion-flattened optical fiber which is suitable for wavelength-division multiplexing soliton transmission utilizing an optical amplifier and the like and has a structure for effectively restraining nonlinear optical phenomena from occurring. The dispersion-flattened optical fiber according to the present invention has, as characteristics at a wavelength of 1550 nm, a dispersion with an absolute value of 5 ps/nm/km or less, an effective cross-sectional area of 45 &mgr;n 2 or more, a dispersion slope of 0.03 ps/nm2/km or less, and a cutoff wavelength of 1.0 &mgr;m or more at a length of 2 m.

Abstract: The present invention relates to an optical transmission line, applicable to Wave Division Multiplexing (WDM) transmission, having a structure for restraining optical transmission characteristics from deteriorating due to each of the occurrence of nonlinear optical phenomena and the wavelength dispersion. This optical transmission line comprises, at least, a first optical fiber having, as characteristics at the predetermined operating wavelength, a first effective area and a first dispersion slope; and a second optical fiber having, as characteristics at the predetermined operating wavelength, a second effective area smaller than the first effective area and a second dispersion slope smaller than the first dispersion slope. In particular, the second optical fiber contributes to suppressing the deterioration in its optical transmission characteristics in the whole optical transmission line.

Abstract: The present invention aims to provide a dispersion-shifted fiber which can effectively restrain nonlinear optical effects from occurring and has a configuration suitable for long-haul light transmission. The dispersion-shifted fiber has, as various characteristics at a wavelength of 1,550 nm, a dispersion level of 1.0 to 4.5 ps/nm/km in terms of absolute value, a dispersion slope not greater than 0.13 ps/nm.sup.2 /km in terms of absolute value, an effective core cross-sectional area not less than 70 .mu.m.sup.2, and a transmission loss not greater than 0.25 dB/km with respect to light in a 1.55-.mu.m wavelength band.

Abstract: The present invention relates to a single-mode optical fiber having a configuration which enables lowering of dispersion slope while securing a sufficient MFD. This single-mode optical fiber has a refractive index profile in which an indent with a sufficient width is provided at the center of its core region. In particular, this indent satisfies the following relationship:a.multidot.(.DELTA.n.sub.2 -.DELTA.n.sub.1)/(b.multidot..DELTA.n.sub.2).gtoreq.0.04when the first core portion in the single-mode optical fiber has a mean relative refractive index difference of .DELTA.n.sub.1 with respect to the cladding portion and an outer diameter of a while the second core portion has a mean relative refractive index difference of .DELTA.n.sub.2 with respect to the cladding portion and an outer diameter of b.

Abstract: This invention relates to a single-mode optical fiber having a configuration for effectively reducing bending loss. In the single-mode optical fiber, while an optical core is constituted by inner and outer cores, an optical cladding is constituted by an inner cladding in which "tailing" occurs and an outer cladding. In particular, in a cross section of the optical fiber perpendicular to the signal light guiding direction, when the surface integral values of relative refractive index difference of the optical cladding and optical core with respect to the outer cladding having an average refractive index n.sub.0 are respectively S1 and S2, the optical fiber satisfies a relationship of S1/S2.gtoreq.0.8.

Abstract: The present invention relates to an S-mode optical fiber having a structure which can effectively restrain dispersion slope from increasing. In this S-mode optical fiber, an optical core is constituted by inner and outer cores, while an optical cladding is constituted by an inner cladding in which "tailing" occurs and an outer cladding. In a cross section of the S-mode optical fiber perpendicular to its signal light propagating direction, when surface integral values of relative refractive index difference with respect to a reference region having an average refractive index n.sub.0 are S1 and S2 in the optical cladding and optical core, respectively, the S-mode optical fiber is designed to satisfy a relationship of 0<S1/S2.ltoreq.0.3. As a result of this configuration, it can effectively restrain dispersion slope from increasing due to "tailing" which inevitably occurs during its manufacturing process.

Abstract: The present invention relates to a dispersion-shifted fiber having a structure which can restrain the bending loss caused by enlargement in mode field diameter from increasing. This dispersion-shifted fiber is a single-mode optical fiber mainly composed of silica glass and has a cutoff wavelength not shorter than the wavelength of signal light at its length of 2 m and a zero-dispersion wavelength within the range of 1.4 .mu.m to 1.7 .mu.m. Further, the mode field diameter in this dispersion-shifted fiber is 9.0 .mu.m or more.

Abstract: The present invention relates to a single-mode optical fiber having a configuration which enables lowering of dispersion slope while securing a sufficient MFD. This single-mode optical fiber has a refractive index profile in which an indent with a sufficient width is provided at the center of its core region. In particular, this indent satisfies the following relationship:a.multidot.(.DELTA.n.sub.2 -.DELTA.n.sub.1)/(b.multidot..DELTA.n.sub.2).gtoreq.0.04when the first core portion in the single-mode optical fiber has a mean relative refractive index difference of .DELTA.n.sub.1 with respect to the cladding portion and an outer diameter of a while the second core portion has a mean relative refractive index difference of .DELTA.n.sub.2 with respect to the cladding portion and an outer diameter of b.

Abstract: There is provided an information processing device having information processing units between which data can be transferred via a bus provided therebetween. A data requested unit which is one of the information processing units sends an answering signal to a data requesting unit which is another one thereof. The information processing device includes an error detecting part for detecting an error in received data, an answering signal generating part for generating an error answering signal with respect to received data having an error and a normality answering signal with respect to received data having no error, and an information sending part for sending the error answering signal to the bus with priority over the normality answering signal.

Abstract: This invention relates to a dispersion-shifted fiber containing silica glass as the major component and in which the zero-dispersion wavelength is set to fall within a range of 1,560 nm to 1,580 nm and the mode field diameter with respect to light having a predetermined wavelength is set to 8 .mu.or more. This dispersion-shifted fiber is a single-mode optical fiber capable of decreasing the influence of nonlinear optical effect and having a structure for suppressing an increase in bending loss of the optical fiber, and includes a core region constituted by the first core portion and the second core portion, and a cladding portion. In particular, an outer diameter a of the first core portion and an outer diameter b of the second core portion satisfy at least a relationship 0.10.ltoreq.a/b .ltoreq.0.29.

Abstract: The present invention relates to a dispersion-shifted fiber having a structure for effectively lowering polarization-mode dispersion. This dispersion-shifted fiber is a single-mode optical fiber mainly composed of silica glass and has a zero-dispersion wavelength set within the range of at least 1.4 .mu.m but not longer than 1.7 .mu.m. In particular, at least the whole core region of the dispersion-shifted fiber contains fluorine.