Abstract: An integrated reconfigurable planar lightwave add-drop (RPLAD) multiplexer for use in a WDM optical communication system is arranged such that each drop port can receive any wavelength channel and each add port can transmit on any wavelength channel. Drop port reconfigurability is achieved by integrating a cross-connect functionality into the RPLAD, illustratively using optical 1×2 switches to perform “space” switching. The switches are controlled from a remotely located node controller. Add port reconfigurability is achieved by having tunable lasers and a wavelength independent optical power combiner, which may be a star coupler that is integrated with the other above-mentioned elements.

Abstract: Techniques and systems for design of optical switch arrays so as to minimize power requirements are described. A design system includes a computer system hosting a design program. The design program receives parameters for the switch array, including a number N of outputs required, and either a maximum number L of stages allowed or maximum and average power requirements allowed. If power requirements are used as parameters, the design program uses N and the power requirements to compute the value of L. The design program then constructs a minimum power sequence of L switches or N switches, whichever is less. If N is less than L+1, N outputs are present and the array is complete. If N is greater than L+1, the design program then adds switches one at a time to the minimum power switch path of the array, until the array provides N outputs.

Abstract: An optical transmission system formed from a plurality of nodes interconnected in a ring configuration via at least two transmission media provides protection capacity for each optical channel. If a channel signal does not meet predetermined criteria, then a loss of signal indication is declared for the channel and one of a plurality of protection switching states is invoked to re-route service traffic carried by the impaired channel to its destination via corresponding protection capacity. The switching states include particular transmission states and at least “keep-alive” and “protection access” states.

Abstract: An integrated reconfigurable planar lightwave add-drop (RPLAD) multiplexer for use in a WDM optical communication system is arranged such that each drop port can receive any wavelength channel and each add port can transmit on any wavelength channel. Drop port reconfigurability is achieved by integrating a cross-connect functionality into the RPLAD, illustratively using optical 1×2 switches to perform “space” switching. The switches are controlled from a remotely located node controller. Add port reconfigurability is achieved by having tunable lasers and a wavelength independent optical power combiner, which may be a star coupler that is integrated with the other above-mentioned elements.

Abstract: The invention disclosed is a circuit for regulating optical power levels. Electrooptic attenuators are used to control optical output intensity by means of feedback loops from the outputs of the attenuators to the electrodes of the attenuators which determine the amount of light going to the outputs. The attenuators may be used in combination with an optical switch array in a wavelength division multiplexing system.

Abstract: An optical intersection with reduced transmission loss is described. An embodiment of the inventive interconnection comprises two intersecting waveguides. According to the teachings of the invention, deleterious asymmetric field distortions in the waveguides, associated with the presence of the adjacent waveguides, are reduced by, for example, changing the width of the intersection region, and the widths of the waveguides as they approach the intersection region.