Embodiments of present invention provide a digital dispersion compensation module. The digital dispersion compensation module includes a multi-port optical circulator and a plurality of dispersion compensation units connected to the multi-port optical circulator, wherein at least one of the plurality of dispersion compensation units includes a first and a second reflectively terminated element and an optical switch being capable of selectively connecting to one of the first and second reflectively terminated elements, and wherein the at least one of the plurality of dispersion compensation units is adapted to provide a substantially zero dispersion to an optical signal, coming from the multi-port optical circulator, when the optical switch connects to the first reflectively terminated element and is adapted to provide a non-zero dispersion to the optical signal when the optical switch connects to the second reflectively terminated element.

Cladding removed from a portion of the optical fiber defines a window exposing the fiber core. A grating having a substantially periodic structure defining a wavelength is moveably positioned in the window, where it can interact with the evanescent field present in the window when optical power is propagating through the fiber. An adjustable positioning fixture holds the grating proximate to the window and operates to change the relative spacing of the fiber core and grating, between: a first position in which the grating is held proximate to the fiber core and substantially interacts with the evanescent field, and a second position in which the grating is held apart from the fiber core and does not substantially interact with the evanescent field.

An optical data center network system including multiple tier-1 optical switches, multiple tier-2 optical switches and multiple tier-3 optical switches is provided. A pod is formed by the tier-1 optical switches connected to each other through ribbon fibers. A macro pod is formed by the tier-2 optical switches connected to each other through ribbon fibers, and each of the tier-2 optical switches is connected to all of the tier-1 optical switches in one pod. The tier-3 optical switches are connected to each other through ribbon fibers, and each of the tier-3 optical switches is connected to all of the tier-2 optical switches in one macro pod. Each optical switch in each tier is implemented by using the Wavelength Selective Switch (WSS) as a basic element, which has been commercialized numerously.

A wavelength selective switch (WSS) includes a liquid crystal on silicon (LCOS) panel and a fiber array with multiple ports. The two outermost ports of the multiple ports are a first port and a second port. An included angle between an intersecting line of the LCOS panel and a first plane in which the incident light entering the LCOS panel and emergent light exiting the LCOS panel are located, and incident light entering the LCOS panel is (90−θ) degrees, where a wavelength of the incident light is same as a wavelength of the emergent light, θ is less than 15 degrees, the first port and the included angle of (90−θ) degrees are located on a same side of the incident light, and the second port and the included angle of (90−θ) degrees are separately located on two sides of the incident light.

An optical system includes an optical waveguide, and a first optical element configured to direct a first ray, having a first circular polarization and impinging on the first optical element at a first incidence angle, in a first direction so that the first ray propagates through the optical waveguide via total internal reflection toward a second optical element. The first optical element is configured to also direct a second ray, having a second circular polarization that is distinct from the first circular polarization and impinging on the first optical element at the first incidence angle, in a second direction that is distinct from the first direction so that the second ray propagates away from the second optical element. The second optical element is configured to direct the first ray propagating through the optical waveguide toward a detector.

This application discloses an optical communications apparatus, which may be a reconfigurable optical add/drop multiplexer. An optical deflection component (211) may perform angle deflection on a plurality of first sub-wavelength light beams to obtain a plurality of second sub-wavelength light beams and a plurality of third sub-wavelength light beams, and propagate the plurality of second sub-wavelength light beams to a second optical switch array (205). A third wavelength dispersion component (206) combines the plurality of second sub-wavelength light beams into a second light beam. A first output component (207) outputs the second light beam from a dimension. A second wavelength dispersion component (208) combines the plurality of third sub-wavelength light beams into a third light beam, and makes the third light beam incident to a third optical switch array (209). A second output component (210) outputs the third light beam to drop a signal.

A method in an optical Wavelength Selective Switch, WSS, for multidirectional switching of optical signals. The optical WSS comprises a reflective element, a first tributary port and a second tributary port. The optical WSS switches (304) an optical signal between the first tributary port and the second tributary port with the reflective element.

An optoelectronic switch comprising: a first plurality of detector remodulators (DRMs) (C3, D1), each DRM having an integer number M of optical inputs and an integer number N of optical outputs; a second plurality of DRMs (C7, D5), each DRM having N optical inputs and M optical outputs; a passive optical switch fabric (C4+C5+C6, D2+D3+D4) connecting the N optical outputs of each of the first plurality of DRMs with the N optical inputs of each of the second plurality of DRMs, the path of an optical signal through the optical switch fabric depending upon its wavelength; wherein each DRM (C3, D1) of the first plurality of DRMs is configured to act as a tunable wavelength converter to select the desired path of an optical signal through the optical switch fabric (C4+C5+C6, D2+D3+D4); and wherein each of the first plurality of DRMs (C3, D1) includes a concentrator, the concentrator configured to aggregate optical signals received from any of the M inputs of that DRM and to buffer them according to the one of the plurality of second DRMs (C7, D5) that includes their destination port.

A MEMS optical switch and a switching node are disclosed. The MEMS optical switch includes N.sub.1 input ports, N.sub.1 input MEMS mirrors, M.sub.1 output ports, and M.sub.1 output MEMS mirrors, where a first input port is configured to transmit a first optical signal to a first input MEMS mirror. The first input MEMS mirror is configured to reflect the first optical signal to a first destination output MEMS mirror, where along a straight line in which a first deflection axis is located, the first input MEMS mirror is located on an edge of the N.sub.1 input MEMS mirrors, and when reflecting the received first optical signal to a first output MEMS mirror and a second output MEMS mirror, the first input MEMS mirror deflects towards an opposite direction relative to a second deflection axis.

An ultra-broadband silicon waveguide micro-electro-mechanical systems (MEMS) photonic switch is provided, which is mainly composed of three parts: input waveguides, a waveguide crossing with a nano-gap, and output waveguides. The waveguide crossing is composed of two identical orthogonal elliptical cylinders. Four ports of the waveguide crossing respectively extend to form single-mode strip waveguides to serve as input/output waveguides. The center of the waveguide crossing is fully etched with a nano-gap. The two symmetrical port waveguides are fully etched with nano-grooves. The lower cladding near the waveguide crossing and the nano-grooves is penetrated and etched. The width of the nano-gap is adjusted through adjusting a voltage applied across both ends of the waveguide crossing, so that a guided-mode directly passes through or is totally reflected. In the disclosure, a propagation path of the photonic switch is switched through adjusting the voltage applied to the waveguide crossing.