Abstract: A distributed network address allocation method is disclosed. For this purpose, an apparatus is provided for use as or in a node of the network. The apparatus comprises a portion (2, 3, 4) for maintaining a seed value n and a state value s. An address (8) of the node is determined from the seed value n by address setting portion (6). A portion (9) is provided for receiving a request from a new node wishing to join the network and itself adapted to perform the method. A portion (10, 12) is provided for generating a proposed seed value using the formula (n+2s) and a proposed state value using the formula (s+1). A portion (14) is provided for offering the proposed seed and state values to the new node. A portion (18) is provided for updating the node's state value s to be the same as that accepted by the new node, if the proposed seed and state values are accepted by the new node. This provides unique address allocation to nodes in a Mobile Ad-Hoc Network.

Abstract: An FSO transceiver (4) comprising a body (6), at least one lens (9) fixed to the body in a first position (C) and means for attaching a connector (11) for an optical fiber (3) at a second position (B) at a predefined distance (Zbc) to the lens, the lens being adapted to converge rays (8) of light sent to the FSO transceiver via free space into the optical fiber. The means for attaching the connector is a temperature compensation device (10) having an expansion coefficient being higher than an expansion coefficient of the body and that the temperature compensation device is fixed to the body in a third position (A) and has a free end which allows the temperature compensation device to expand or contract according to temperature changes, and that the second position is positioned between the third position and the first position.

Abstract: A germanate glass composition suitable for use in a fiber amplifier for broadband amplification of optical signals is provided. The glass preferably includes 35-75% GeO2, 0-45% PbO, 5-20% BaO, 5-20% ZnO, and 2-10% R2O (R=Na, Li, K). It is doped with thulium ions (Tm3+) and codoped with holmium ions (Ho3+). The glass composition of results in a remarkably large bandwidth as compared with previous glasses. It is also highly compatible with existing silica optical fibers.

Abstract: In a calibration method, the relation between dopant concentrations of ?-doping layers in a multilayered semiconductor structure and process parameters is determined S1 based on multiple bulk specimens of the material in which the ?-doping layers are located. A desired dopant concentration is selected S2, and the semiconductor structure with predetermined doping levels can be generated S3 based on the relation between the process parameters and the predetermined doping concentrations.

Abstract: In the present invention, a single-frequency tone is used as addressing header for each optical packet. The frequency of the single-frequency tone is situated within the baseband of the digital payload signal and is preferably a radio-frequency tone. The single-frequency tone is multiplexed with the digital payload and modulated into an envelope of an optical carrier. The frequency is indicative of an address or out-port for the optical packet, which means that different destinations in the network correspond to different frequencies. When switching such an optical packet, the power of the frequency tone is measured. If a tone is present, the optical path corresponding to the allocation is opened by an electronic switch control, and when the tone disappears, the path is closed. Due to the narrow bandwidth of the frequency tone, any disturbance of the digital payload is essentially negligible.

Abstract: A germanate glass composition suitable for use in a fiber amplifier for broadband amplification of optical signals is provided. The glass preferably includes 35-75% GeO2, 0-45% PbO, 5-20% BaO, 5-20% ZnO, and 2-10% R2O (R=Na, Li, K). It is doped with thulium ions (Tm3+) and codoped with holmium ions (Ho3+). The glass composition of the invention results in a remarkably large bandwidth as compared with previous glasses. It is also highly compatible with existing silica optical fibers.

Abstract: A tellurite glass composition doped with a first lanthanide, preferably Tm, and codoped with another lanthanide oxide, e.g. Ho, is provided. The glass includes 4-12 mole % of alkalihalide XY, X being selected from the group of Li, Na, K, Rb, Cs and Fr and Y being selected from the group of F, Cl, Br and I. A preferred glass contains about 10 mole % of the alkalihalide CsCI. The addition of alkalihalide XY results in an enhanced energy transfer from the first to the second lanthanide ion, whereby the lower energy level of the first lanthanide ion is depopulated. The ratio between upper and lower energy level lifetimes for the first lanthanide ion can be reduced to a value below one, enabling efficient amplifier fibers.

Abstract: Method and apparatus for polarizing light propagating in an optical fiber. The apparatus has an optical fiber having a Fiber Bragg Grating (FBG) section of predetermined length therein, and a force applying device for applying a lateral force to a predetermined portion of the FBG section. The predetermined portion comprises a predetermined percentage of the predetermined length. When the predetermined percentage is equal to or greater than about 10 percent, two polarization states for the light passing through the optical fiber are obtained. When the predetermined percentage is a small portion of the grating length, for example, about 1 percent of the length of a chirped grating, a finely tunable optical fiber polarizer is provided. The apparatus can use standard optical fiber such as telecomm fiber and provides various advantages including the capability of being switched on and off by simply applying and withdrawing the lateral force.