Fujitsu Corporation

Akira Miyauchi

Kazuo Yamane

Satoru Okano

Yumiko Kawasaki

Hiroshi Nishimoto

Masahiro Sugimoto

Tadashi Okiyama

Shinji Emori

Hiroo Kitasagami

Haruo Tamada

Satoru Fujitsu Hokkaido Digital Tech Ltd Okano

In an optical transmission system comprising a transmitter, a receiver, and a transmission line that connects the transmitter and the receiver, a dispersion compensator is disposed in the receiver. The transmitter comprises an E/O (electro-optical signal converter) and a post-amplifier. An optical signal that has been RZ-coded is supplied to the E/O. The transmitter pre-chirps the optical signal. The pre-chirp is performed by red-chirp of which the value of the chirping parameter &#x3b1; is positive. When the pre-chirp is performed, the non-linear effect of the optical signal on the transmission line can be canceled. In addition, with the RZ coded signal, the inter-symbol interference can be alleviated. Thus, the total dispersion amount of the dispersion compensator can be suppressed. In addition, the power of the optical output can be increased.

Optical transmission system and dispersion compensator

In a system connecting a transmitter and a receiver using transmission paths and repeaters (in-line amplifiers), red chirping whose &#x3b1; parameter is performed for an optical signal on a transmitting side. Each of the repeaters includes a dispersion-compensator for compensating the amount of dispersion on a preceding transmission path. The amount of dispersion compensation of the dispersion-compensator included in the transmitter is made constant. The dispersion-compensator included in the receiver is arranged in order to compensate the amount of dispersion on a preceding transmission path. A spread of a pulse width on a transmission path can be efficiently compensated by using the compensation capability of the dispersion-compensators and the red chirping on the transmitting side.

Optical transmission system using in-line amplifiers

In a system connecting a transmitter and a receiver using transmission paths and repeaters (in-line amplifiers), red chirping whose &#x3b1; parameter is positive is performed for an optical signal on a transmitting side. Each of the repeaters includes a dispersion-compensator for compensating the amount of dispersion on a preceding transmission path. The amount of dispersion compensation of the dispersion-compensator included in the transmitter is made constant. The dispersion-compensator included in the receiver is arranged in order to compensate the amount of dispersion on a preceding transmission path. A spread of a pulse width on a transmission path can be efficiently compensated by using the compensation capability of the dispersion-compensators and the red chirping on the transmitting side.

In an optical transmission system comprising a transmitter, a receiver, and a transmission line that connects the transmitter and the receiver, a dispersion compensator is disposed in the receiver. The transmitter comprises an E/O (electro-optical signal converter) and a post-amplifier. An optical signal that has been RZ-coded is supplied to the E/O. The transmitter pre-chirps the optical signal. The pre-chirp is performed by red-chirp of which the value of the chirping parameter &agr; is positive. When the pre-chirp is performed, the non-linear effect of the optical signal on the transmission line can be canceled. In addition, with the RZ coded signal, the inter-symbol interference can be alleviated. Thus, the total dispersion amount of the dispersion compensator can be suppressed. In addition, the power of the optical output can be increased.

In a system connecting a transmitter and a receiver using transmission paths and repeaters (in-line amplifiers), red chirping whose a parameter is positive is performed for an optical signal on a transmitting side. Each of the repeaters includes a dispersion-compensator for compensating the amount of dispersion on a preceding transmission path. The amount of dispersion compensation of the dispersion-compensator included in the transmitter is made constant. The dispersion-compensator included in the receiver is arranged in order to compensate the amount of dispersion on a preceding transmission path. A spread of a pulse width on a transmission path can be efficiently compensated by using the compensation capability of the dispersion-compensators and the red chirping on the transmitting side.

A chirping parameter .alpha. in a transmitter is set to a positive value with respect to an SMF that has a positive dispersion value with respect to signal light. A dispersion compensator is provided not only at the receiving end but also at the transmitting end. This achieves a reduction in the number of types of dispersion compensators that should be prepared in advance to optimize transmission characteristics despite the variety in the lengths of transmission fibers.

Optical transmission system

An integrated circuit device including: at least one semiconductor chip (3) having a plurality of circuit elements; a package (21 to 24) enclosing the semiconductor chip with a hermetic seal; and a strip line unit (15-2, 11-1b, 11-2, 20 and 23:15-1, 11-1, 11-2, 11-3, 12-1 and 20) for connecting the circuit elements in the semiconductor chip to circuit outside of the package. The stripline unit having a microstrip line structure and a triplate strip line structure serial-connected to the microstrip line structure and connecting the outside circuits. The triplate strip line structure has a characteristic impedance equal to that of the microstrip line structure so that the strip line unit satisfies the required impedance matching. A center of the conductive layer strip line of the triplate strip line structure has a smaller width than that of a microstrip line of the microstrip line structure to have a predetermined impedance so that the triplate strip line structure has a same characteristic impedance as that of the microstrip line structure.

Integrated circuit device having strip line structure therein

An integrated circuit device including a stacked layer unit having a plurality of stacked layers each having an insulation layer and at least one conductive layer strip formed on a surface of the insulation layer, and at least one chip mounted on the top of the insulation layer and having a plurality of circuit elements. The IC device also includes at least one first conductive member formed in the stacked layer unit, having a low inductance for first signals applied thereto and operatively connecting the first signals to be transferred between the circuit elements. The IC device further includes at least one second conductive member formed in the stacked layer unit, having a higher inductance for the first signals than that of the first conductive member and operatively connecting second signals to be transferred between the circuit elements the stacked layer unit, the chip, and the first and second conductive members are enclosed by a package and sealed with a hermetic seal.

Integrated circuit device having stacked conductive layers connecting

A semiconductor device provided with signal lines which connect a chip, provided at a top portion of a package, with external terminals provided at a bottom portion of the package. The signal lines have portions formed along side surfaces of the package. Ground surfaces are formed at predetermined distances on two sides of the high-speed signal lines. A coplanar waveguide is formed by the high-speed signal lines and the ground surfaces, so the impedance of vertical portions of the high-speed signal lines is matched to the circuits connected thereto.

Growing community of inventors

Kawasaki, Japan

Akira Miyauchi