Infrared reflectance and Raman spectra of LBO crystals were recorded at room temperature and liquid nitrogen temperature. The vibrational modes are classified by the factor group analysis method and the spectral bands are assigned to vibrations of the (B306)3-ring and BO, tetrahedra.

No abstract

The cascade EDFAs have to be used if the distance between nodes is extremely long in WDM network. However, the gain spectrum of normal EDFA is not flat. This will become much serious as the number of cascade EDFAs is huge. The gain spectrum is studied both theoretically and experimentally in this paper. A special designed FP filter is used to compensate the gain difference after cascade EDFAs used.

No abstract

Power management is discussed based on a WDM optical test network, in which ring laser clamped EDFAs are used to compensate loss and only the optical attenuators is needed for power regulation. All channels at the output of each node are adjusted to a preset power level, so signal power fluctuations and differences between channels are not passed to the later nodes. The transmission performance is also studied and a simple expression is derived for evaluating the possible input power to the fiber and the possible transmission distance in optical networks. The accumulation of optical amplifier noise and the maximum input power for the stable gain of the lasing-clamped EDFA are the dominant factors limiting the network scale, and restrict the preset input power to the fiber.