An apparatus for management of a spectral capacity of a wavelength division multiplexing, WDM, system includes at least one pair of transmission fibers provided for transporting optical signals. Each transmission fiber of a transmission fiber pair is connected to a first port of an optical circulator having at least two additional ports and adapted to transmit an incoming optical signal entering one of its ports via its next port. WDM subsystems configured with counter-propagating assignable wavelengths are connected to associated ports of the optical circulator of the apparatus.

An apparatus includes a reconfigurable optical add/drop multiplexer (ROADM) having an input port to receive a first optical signal from a second device. The ROADM also includes a first wavelength selective switch (WSS), in optical communication with the input port, to convert the first optical signal into a second optical signal, a loopback, in optical communication with the first WSS, to transmit the second optical signal, and a second WSS, in optical communication with the loopback, to convert the second optical signal to a third optical signal and direct the third optical signal back to the second device via the input port.

Process margin relaxation is provided in relation to a compensated-for process via a first optical device, fabricated to satisfy an operational specification when a compensated-for process is within a first tolerance range; a second optical device, fabricated to satisfy the operational specification when the compensated-for process is within second tolerance range, different than the first tolerance range; a first optical switch connected to an input and configured to output an optical signal received from the input to one of the first optical device and the second optical device; and a second optical switch configured to combine outputs from the first optical device and the second optical device.

A distributed antenna system comprises: one or more access units configured to receive multiple downlink radio frequency signal sets, and further configured to convert the multiple downlink radio frequency signal sets into multiple downlink optical signal sets; a first wavelength division multiplexing unit configured to multiplex the multiple downlink optical signal sets to generate a first wavelength division multiplexing optical signals; a first wavelength division demultiplexing unit configured to demultiplex the first wavelength division multiplexing optical signals to obtain the multiple downlink optical signal sets; a first optical fiber, coupled between the first wavelength division multiplexing unit and the first wavelength division demultiplexing unit, and configured to transmit the first wavelength division multiplexing optical signal; and multiple first remote units coupled to the first wavelength division multiplexing unit, and configured to convert the multiple downlink optical signal sets into the multiple downlink radio frequency signal sets for transmission.

An optical communications network comprises optical data links interconnected by add-drop nodes, the optical data links comprising data channels. The data channels are allocated into equal-sized bins. In response to a first data channel request between a given source-destination pair, one of the equal-sized bins is assigned to the data channel request. In response to requests for additional bandwidth for the same source-destination data channel request, unused channels within the assigned equal-sized bin are allocated to the data channel request. In response to subsequent data channel requests between different source-destination pairs, additional unallocated equal-sized bins are assigned to the subsequent data channel requests. In response to subsequent data channel requests when resource sharing for one equal-sized bin, data channels in the last equal-sized bin are assigned using the reverse channel assignment process. Reverse channel assignment can also be used for other bins as an option.

Embodiment of present invention provide a micro-optics module. The module includes a glass body of pentagon shape having five side surfaces including an upper side surface, a left side and a right side surface next to the upper side surface, a lower side surface next to the left side surface, and a 5th side surface next to and between the lower side surface and the right side surface. The glass body is adapted to, upon incident of a first optical signal at the left side surface, cause the first optical signal to propagate toward and exit the glass body at the right side surface and, upon incident of a second optical signal at the right side surface, cause the second optical signal to reflect back at the left side surface; reflect back at the 5th side surface; and finally exit the glass body at the upper side surface.

A wavelength division multiplexing device includes a common port and a plurality of filters that define an optical path. The common port includes a collimator that transmits an optical beam including a plurality of optical signals. Each optical signal is associated with a different wavelength range, and each filter includes an interface having a radius of curvature. One filter is configured to receive the optical beam from the collimator, transmit an optical signal through its interface, and reflect the remaining portion of the optical beam toward another filter. The common collimator and filter are configured so that the reflected portion of the optical beam has a beam waist located in the optical path midway between the filters, and a wavefront radius of curvature at the other filter that matches the filter radius of curvature of that filter. A method of processing light in such a device is also disclosed.

Planar assemblies for coupling a plurality of optical transceivers to the same optical fiber. For example, the optical transceivers may be PON transceivers functioning according to different data rates and/or different modulation formats. Each optical transceiver communicates using one or more different wavelength channels. At least some of the disclosed planar assemblies are scalable to couple various numbers of optical transceivers to the same end face of an optical fiber, e.g., by fixing a corresponding number of passive, slab-like optical filters to a substantially planar surface of the support substrate to which the optical transceivers are also fixed adjacent and along. Some embodiments may employ various bulk lenses fixed to said planar surface to suitably relay light-beam segments between the end face of the fiber and the optical transceivers and/or between the different slab-like optical filters.

Process margin relaxation is provided in relation to a compensated-for process via a first optical device, fabricated to satisfy an operational specification when a compensated-for process is within a first tolerance range; a second optical device, fabricated to satisfy the operational specification when the compensated-for process is within second tolerance range, different than the first tolerance range; a first optical switch connected to an input and configured to output an optical signal received from the input to one of the first optical device and the second optical device; and a second optical switch configured to combine outputs from the first optical device and the second optical device.

An optical communications network comprises optical data links interconnected by add-drop nodes, the optical data links comprising data channels. The data channels are allocated into equal-sized bins. In response to a first data channel request between a given source-destination pair, one of the equal-sized bins is assigned to the data channel request. In response to requests for additional bandwidth for the same source-destination data channel request, unused channels within the assigned equal-sized bin are allocated to the data channel request. In response to subsequent data channel requests between different source-destination pairs, additional unallocated equal-sized bins are assigned to the subsequent data channel requests. In response to subsequent data channel requests when resource sharing for one equal-sized bin, data channels in the last equal-sized bin are assigned using the reverse channel assignment process. Reverse channel assignment can also be used for other bins as an option.