Abstract: An apparatus and method are provided for amplifying a signal having several multiplexed channels of different wavelengths. In one embodiment, an amplifier 100 is provided having a doped fiber 120 coupled to an input 105, a pump 145 coupled to the doped fiber to provide an output to amplify the signal therein and a control system 130 for controlling the pump. The control system 130 has a detector 170 for measuring power of the signal and a controller 180 for adjusting power to the pump 145 based on predetermined criteria and the measured signal power. The pump power is adjusted as a linear function of the signal power by including within the predetermined criteria a multiplier by which the signal power is multiplied, and an offset that is added to the product of the multiplier and the signal power to ensure that the power applied to the pump 145 is non-zero even for zero signal power.

Abstract: A method of building and assembling programs across computer networks that is dictated by the user to perform logical work without the user using a compiler. Users are able to assemble programs over a network by defining or re-defining which logical components are bound into the overall program without the use of a compiler. Logical components are called and bound into the program at run time, allowing dynamic programming which may be modified at any time without re-compiling the entire program. Each logical component can act independently of other logical components or work in concert with each other. This allows assembly of a program, even though some components may be created using totally different methodologies and/or are constructed by different programmers.

Abstract: A cache system has a multilevel cache architecture. An L1 cache receives instructions from an external memory. An L0 cache has a first predetermined number L0 of cache lines for receiving instructions from the L1 cache. An assist cache has a victim cache and a prefetch cache. The victim cache stores a second predetermined number VC of cache lines, and the prefetch cache stores a third predetermined number PC of cache lines. The victim cache receives instructions from the L0 cache. The prefetch cache receives instructions from the L1 cache. A victim filter stores a fourth predetermined number VF of addresses wherein VF is a function of L0 and a number of cache writes. The number of cache writes to the L0 and the victim cache is reduced relative to using the L0 cache without the assist cache.

Abstract: A four-port Wavelength-Division-Multiplexing (WDM) element is disclosed that can be employed for various purposes in optical communication networks, particularly in bi-directional fiber optic lines. In one embodiment, one four-port WDM element is used with one optical amplifier to provide bi-directional propagation on the same fiber. In another embodiment, the four-port element is used in conjunction with optical attenuators to provide for gain equalization of channels and the flexibility to add or remove channels. In yet another embodiment, input and output ports are added to current-art elements thereby enabling bi-directional operation to be achieved with equipment that does not provide such capabilities.

Abstract: A method of deriving a pre-distorter for a corresponding non-linear amplifier is disclosed. The first step of the method is to form the pre-distorter's topology. This is done by first determining a corresponding inverse topology to the non-linear amplifier's topology. The non-linear amplifier has a topology comprising filter and non-linear amplifier elements. The inverse topology comprises corresponding inverse filter and amplifier elements to the amplifier's filter and non-linear amplifier elements. Then, those of the inverse filter and amplifier elements for which compensation with the pre-distorter is desired are selected. Any of the inverse filter and amplifier elements that were not selected are then removed from the inverse topology to form the pre-distorter's topology. Thus, the pre-distorter's topology comprises the selected inverse filter and amplifier elements.