Shigendo Nishi

80 Gb/s optical soliton transmission over 80 km with time/polarization division multiplexing

Time/polarization-division multiplexed optical solitons are successfully transmitted at 80 Gb/s over an 80 km dispersion-shifted single-mode-fiber. The 80 Gb/s optical pulse trains are generated by optically multiplexing 10 Gb/s gain-switched pulse trains. The transmitted solitons are demultiplexed with a polarization beam splitter and two intensity-modulators driven by a 10 Gb/s electrical timing recovery circuit. No error-rate floor is observed.<<ETX>>

160 Gb/s sub-picosecond transform-limited pulse signal generation utilizing adiabatic soliton compression and optical time-division multiplexing

0.8 ps TL pulses are successfully generated from a gain-switched DFB-LD by adiabatic soliton compression using a dispersion decreasing fiber (DDF). The compression ratio can be controlled using the peak input power into the DDF. We obtain a 10/spl times/2/sup n/ Gb/s pulse stream by optically multiplexing the compressed pulses with a Mach-Zehnder (MZ) interferometer type multiplexer, in which n can be freely selected from 1 to 4 by controlling the coupling ratios of the couplers in the MZ interferometers. By using the demonstrated techniques, we can multiplex the initial pulse stream up to 160 Gb/s at the noninterfering duty factor of 0.2.<<ETX>>

Adiabatic soliton compression of gain-switched DFB-LD pulse by distributed fiber Raman amplification

Using a dispersion-shifted single-mode fiber pumped by laser diodes as a distributed fiber Raman amplifier, the authors adiabatically compressed transform-limited (TL) pulses generated by a gain-switched distributed-feedback laser diode followed by linear compression and a spectral window. The initial TL pulses were successfully compressed asymptotically to almost pure solitons as short as 3.6 ps at the 2.4 dB total gain of a distributed fiber Raman amplifier, even without using solitons as the initial pulses. The experimental results are well supported by numerical calculations made with the beam propagation method.<<ETX>>

20 Gb/s optical soliton data transmission over 70 km using distributed fiber amplifiers

20 Gb/s optical soliton data transmission is demonstrated over 70 km. Highly efficient distributed Raman amplifiers for fiber-loss compensation are realized by using high Delta n dispersion-shifted single-mode fibers pumped by laser diodes. To achieve high bit rate transmission, optical multiplexing and demultiplexing techniques are also employed. The bit error rate (BER) performance dependence on the input peak power of the optical pulse is measured. No power penalty can be seen at the input peak power required for transmitting optical solitons while the BER performance degrades when decreasing the input peak power.<<ETX>>

Optical protection switches for trunk transmission systems

Two different types of optical matrix switches are presented for use as protection switches. One is an optoelectronic matrix switch using Si pin photodiodes. The first switch configuration offers two advantages for large matrix fabrication: high off-state output impedance and no electrical power requirement for establishing the off-state. The other is an optical-wavelength-division matrix switch, using an acoustooptic deflector, which requires minimal hardware for switching and realizes unlimited bandwidth. The switching speed, crosstalk, attainable matrix size, and optical source requirements are evaluated for both switches. Their protection system application schemes are clarified.<<ETX>>

3.6 Gb/s all laser-diode optical soliton transmission

3.6-Gb/s optical soliton transmission using a gain-switched 1.55- mu m distributed-feedback laser diode and a Ti:LiNbO/sub 3/ intensity modulator is demonstrated. An Er/sup 3+/-doped fiber amplifier and a Raman amplifier, both pumped by 1.48- mu m laser diodes, are used for achieving intense optical pulses and fiber-loss compensation, respectively. The intensity-modulation direct-detection optical receiver of a commercial F-1.6 G system is used to measure the bit-error rate.<<ETX>>

60 Gb/s/spl times/2 ch time/polarization-multiplexed soliton transmission over 154 km utilizing an adiabatically compressed, gain-switched, DFB-LD pulse source

Time/polarization-division multiplexed optical solitons are successfully transmitted at 120 Gb/s over 154 km. The transmitted solitons are generated from an adiabatically compressed transform-limited gain-switched DFB-LD pulse source, and demultiplexed with a polarization beam splitter and three cascaded intensity-modulators driven by a 7.5 GHz timing recovery circuit. No error-rate floor is observed.<<ETX>>

5 Gb/s optical soliton transmission experiment using Raman amplification for fiber-loss compensation

Optical soliton transmission of 5 Gb/s over a 23-km amplification spacing using a gain-switched 1.55- mu m distributed feedback laser diode and Ti:LiNbO/sub 3/ intensity modulator is discussed. An Er/sup +/-doped fiber amplifier, pumped by 1.45- and 1.48- mu m laser diodes, is employed for achieving intense optical pulses. Transmission fiber-loss is completely compensated for by Raman amplification using by 1.45- and 1.48- mu m laser-diode pumping. A bit error rate (BER) of 2*10/sup -10/ has been obtained.<<ETX>>