Abstract: Various example embodiments are disclosed. According to an example embodiment, a dual split passive optical network (PON) may be provided that includes an optical splitting device, and a first and second distribution fibers connected to the optical splitting device. A first cyclic AWG may be coupled to the optical splitting device via the first distribution fiber and a second cyclic AWG may be coupled to the optical splitting device via the second distribution fiber. In other example embodiments, an asymmetric power splitting ratio may be used for the splitting device, or optical seeds and/or optical data signals may be allocated to each of the cyclic AWGs based on a performance of the optical data signals and/or power loss/attenuation of the respective distribution fibers.

Abstract: Various example embodiments are disclosed. According to an example embodiment, a dual split passive optical network (PON) may be provided that includes an optical splitting device, and a first and second distribution fibers connected to the optical splitting device. A first cyclic AWG may be coupled to the optical splitting device via the first distribution fiber and a second cyclic AWG may be coupled to the optical splitting device via the second distribution fiber. In other example embodiments, an asymmetric power splitting ratio may be used for the splitting device, or optical seeds and/or optical data signals may be allocated to each of the cyclic AWGs based on a performance of the optical data signals and/or power loss/attenuation of the respective distribution fibers.

Abstract: Systems and methods for verifying performance at an intermediate point in an optical link are provided by virtue of one embodiment of the present invention. One application is locating a fault along a long optical link while minimizing the need for trained personnel to inspect and monitor the link at numerous widely separated locations. At an intermediate point in the link, a portion of the optical signal present is tapped off and demodulated. By use of error correction decoding techniques on the demodulated data, the performance of the link up until that intermediate point may be verified.

Abstract: A efficient and inexpensive optical WDM network architecture with add and drop couplers. Add couplers and drop couplers connected to a network optical fiber with wavelength blocker units which filter out optical signals at selected wavelengths on the optical fiber. The wavelength blocker units are distributed among the add and drop couplers so that each segment of the optical fiber between pairs of neighboring wavelength blocker units has at least three add and drop couplers. More specifically, each segment has the following relationship: THRU+ADD+DROP+LOCAL?TOTAL where THRU is the number of channels passing through the segment; ADD is the number of channels added within the segment; DROP the number of channels dropped within the segment; LOCAL the number of channels confined within the segment; and TOTAL is the total capacity of the optical fiber.

Abstract: Systems and methods for controlling power of WDM channels in a WDM receiver. A preamplifier is provided prior to a demultiplexer in the WDM receiver chain. The gain of the preamplifier may be controlled based on power measurements made on individual WDM channels. A filter with controllable tilt may be employed to compensate for amplifier gain tilt and assure that all of the WDM channels remain within the dynamic range of the photodetector and receiver electronics. This provides improved bit error rate performance.

Abstract: The present invention proposes a method and a device to add and drop optical channels in an optical transmission system (1) in which a multi-channel optical signal is transmitted into an optical fiber line (300).

Abstract: An optical transmission system has been designed to optimize the use of the spectral emission range of rare-earth-doped fiber amplifiers. The system includes a wide band of channels in the spectral emission range of erbium-doped fiber amplifiers, which is split into two sub-bands, a low sub-band corresponding to the low end of the range and a high sub-band corresponding to the high end of the range. The two sub-bands are separately amplified and optimized, and then recombined without significant competition between the two sub-bands. In addition, an equalizing filter, such as a specialized Bragg filter or interferential filter, is applied to the low sub-band instead of the entire band of channels, thus greatly reducing any equalization need or unequalization effects.