Masahiro Daikoku

100Gbit/s DQPSK Transmission Experiment without OTDM for l00G Ethernet Transport

We demonstrate 100Gbit/s DQPSK transmission experiment over 50km SMF. Without resorting OTDM, 100Gbit/s transmission was enabled with DQPSK format and commercially available electronics. Possibility of DQPSK modulation for future 100G Ethernet transport is verified.In order to realize a future 100-Gb Ethernet (100 GbE) transport, 100-Gb/s transmission without 100-GHz-class electronics and optical time-division-multiplexing technique was demonstrated. By using a differential quadrature phase-shift-keying (DQPSK) modulation format and commercially available electronics, 2- and 50-km transmissions of 100-Gb/s signal were successfully achieved over a standard single mode fiber. The receiver sensitivity, chromatic dispersion, and differential group delay tolerances of 100-Gb/s DQPSK signal were also evaluated. Through these evaluations, the possibility of DQPSK modulation for future 100-GbE transport is verified

160-Gb/s four WDM quasi-linear transmission over 225-km NZ-DSF with 75-km spacing

A 160-Gb/s four wavelength-division-multiplexing quasi-linear signal transmission was demonstrated over a 225-km nonzero dispersion-shifted fiber with 75-km spacing by using alternating polarization optical time-division multiplexing. A Q factor of about 15.0 dB was obtained after transmission on average. It was experimentally verified that exact adjustment of the dispersion compensation fiber is required with a few picosecond/nanometer steps on each channel after transmission.

Optical 40-gb/s 3R regenerator with a combination of the SPM and XAM effects for all-optical networks

An all-optical 3R regenerator with a combination of self-phase modulation (SPM) and cross-absorption modulation (XAM) effects is proposed and investigated. Principle performances of the proposed all-optical 3R regenerator were experimentally investigated at a signal bit rate of 40 Gb/s. The all-optical 3R regenerator, which is located at the midpoint of a 1080-km transmission line, successfully provided an approximately 3-dB improvement of the Q-factor both just after regeneration and after totally 1080-km transmission. The chromatic dispersion tolerance of the proposed 3R regenerator was also investigated and successfully enhanced to about twice as wide by introducing a predistortion block configuration including a highly nonlinear fiber (HNLF). It was confirmed that the proposed all-optical 3R regenerator can become one of the strong candidates for the actual deployment of the all-optical network

Performance comparison of modulation formats for 40 Gbit/s DWDM transmission systems

The performance of various modulation formats, namely OOK, DPSK and DQPSK with and without RZ carving, were experimentally compared to clarify the optimum modulation formats for 40 Gbit/s DWDM transmission systems with 50 GHz channel spacing.

8/spl times/160-Gb/s WDM field transmission experiment with single-polarization RZ-DPSK signals and PMD compensator

Single-polarization 160-Gb/s-based wavelength-division-multiplexing (WDM) field transmission has been successfully demonstrated. By using a return-to-zero differential phase-shift-keying modulation format and a simple polarization-mode dispersion compensator, we have successfully demonstrated single-polarization 8/spl times/160 Gb/s WDM transmission without the polarization demultiplexing.

Highly reliable optical bidirectional path switched ring networks applicable to photonic IP networks

The reliability of the optical bidirectional path switched ring (OBPSR) network is studied by using optical networking equipment (ONE) with microelectromechanical system (MEMS)-based optical switching fabrics. The reliability of the wavelength path in OBPSR networks is shown to be highly dependent on redundant schemes of switching fabrics in the ONE. This study proposes a new redundant scheme utilizing optical couplers together with controlled switch fabrics without using active selectors, and shows that reliability of the wavelength path can be remarkably improved. A fast redundant switching operation of 10 ms was experimentally confirmed with a prototype of the ONE based on the proposed redundant switching fabrics. Furthermore, interworking operations in terms of the protection and restoration between the optical layer and the Internet protocol (IP) layer are experimentally investigated. In a 500-km optical ring network, fast wavelength path protection switching was confirmed without reconfiguring the link state database of the IP layer, and the measured protection time in the IP layer was as short as 21 ms.

Field trial of 63 channels 40 Gbit/s dispersion-managed soliton WDM signal transmission over 320 km NZ-DSFs

Field trial of 63 channels 40 Gbit/s dispersion-managed soliton WDM signal transmission was successfully demonstrated over 320 km (4 /spl times/ 80 km) installed NZ-DSFs. The obtained Q factor on average was 15.4 dB, and very stable long-term performance was confirmed without PMD compensation.

Study of 40 Gbit/s Modulation Format to Upgrade 10 Gbit/s Long-Haul Transmission Systems with 50 GHz Channel Spacing

The optimum 42.7 Gbit/s modulation format to upgrade 10.7 Gbit/s transmission systems with 50 GHz channel spacing was studied. RZ-DQPSK was more suitable than duobinary, since 1600 km transmission was achievable with a wider tolerance to PMD.

Investigation of system upgradability over installed fiber-optic cable using 40-Gb/s WDM signals toward multiterabit optical networks

An investigation of system upgradability of installed fiber-optic cable was conducted using 40-Gb/s wavelength-division-multiplexing (WDM) signals toward multiterabit optical networks. A field trial of 63-channel 40-Gb/s dispersion-managed soliton WDM signal transmission was successfully demonstrated over 320-km (4 /spl times/ 80-km) installed nonzero-dispersion-shifted fibers. The average Q factor of 15.4 dB was obtained, and very stable long-term bit-error-ratio performance was confirmed without polarization-mode dispersion compensation. This system upgradability investigation in the field environment provided the confidence to introduce 40-Gb/s technologies and effectively to construct multiterabit optical networks following the demand increase in the future.

A demonstration of fast optical bidirectional line switched ring protection in IP-based optical switching network

The OBLSR protection architecture using the ONPE was introduced into the IP network. The all-optical protection effectively achieved a faster protection of IP packets than OSPF-based IP layer protection. We demonstrated the protection time for IP layer to be less than 21 milliseconds in a 500 km bi-directional ring network by using the OBLSR protection and the proper guard time of IP routers.