Wavelength division multiplex (WDM) photonic networks are expected as the key for the global communication infrastructure. Recent increase of communication demands require large-scale highly-dense WDM systems, which results in severe requirements for optical cross-connect systems, such as cross-talk specification. In this paper, we propose a new optical path cross-connect system (OPXC) using matrix-WDM scheme, which makes it possible to reduce cross-talk requirements of WDM filters and to construct OPXC in modular structures. The matrix-WDM scheme is a concept of two-layered optical paths, which provides wavelength group managements in the fiber dispersion equalization and EDFA gain equalization.

Wavelength Division Multiplex (WDM) photonic networks are expected as key for global communication infrastructure. The accurate measurement methods for AWG-MUX/DMUX are desirable for WDM network design. We measured a transfer function matrix of an AWG-MUX to find that polarization mode dispersion (PMD) and polarization dependent loss (PDL) shows the bandpass characteristics, which may limit the maximum size and the bit rate of the system. These bandpass characteristics of PMD and PDL are reproduced by a simple AWG-MUX model: The phase constant difference of 0.5% between orthogonal modes in arrayed waveguides is sufficient to obtain the measured passband characteristics of PMD and PDL. We find phase distribution difference between two orthogonal modes in the arrayed waveguide grating gives arise to complex PMD.

Wavelength Division Multiplex (WDM) photonic networks are expected as key for global communication infrastructure. The accurate measurement methods for AWG-MUX/DMUX are desirable for WDM network design. We measured a transfer function matrix of an AWG-MUX to find that polarization mode dispersion (PMD) and polarization dependent loss (PDL) shows the bandpass characteristics, which may limit the maximum size and the bit rate of the system. These bandpass characteristics of PMD and PDL are reproduced by a simple AWG-MUX model: The phase constant difference of 0.5% between orthogonal modes in arrayed waveguides is sufficient to obtain the measured passband characteristics of PMD and PDL. We find phase distribution difference between two orthogonal modes in the arrayed waveguide grating gives arise to complex PMD.

Photonic ATM switching systems with Terabit/s throughput are desirable for future broadband ISDN systems. Since electronic LSI-based ATM switching systems are planned to have the throughput of 160Gb/s, a photonic ATM switching system should take the role of the highest layer in a hybrid switching network which includes electronic LSI-based ATM switching systems as its sub-system. This report discusses the state-of-the-art photonic devices needed for a frequency-self-routing ATM photonic switching system with maximum throughput of 5Tb/s. This kind of systems seems to be a moderate system for the first phase photonic switching system with no insuperable obstacle for initiating development, even though none of the devices and technologies required have yet been developed to meet the specifications. On the contrary, for realizing further enlarged throughput as the second-phase photonic switching system, there are huge fundamental research projects still remaining for establishing the technology utilizing the spectrum broadened over 120nm and highly-dense FDM technologies based on homodyne coherent detection, if supposing a simple architecture. "Ultra devices" seem to be the photonic devices based on new tailored materials of which gain and refractive index are designed to realize ultra-wide spectrum utilization.

We propose a novel Bragg grating filter synthesis method using a Fourier transform of the target scattering matrix. Multiple scattering processes are taken into account by iteration to improve the synthesis accuracy.

Wavelength division multiplex (WDM) photonic networks are expected as the key for the global communication infrastructure. Recent increase of communication demands require large-scale highly-dense WDM systems, which results in severe requirements for optical cross-connect systems, such as cross-talk specification. In this paper, we propose a new optical path cross-connect system (OPXC) using matrix-WDM scheme, which makes it possible to reduce cross-talk requirements of WDM filters and to construct OPXC in modular structures. The matrix-WDM scheme is a concept of two-layered optical paths, which provides wavelength group managements in the fiber dispersion equalization and EDFA gain equalization.