Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for optical communications. In one aspect, an optical circulator array includes a plurality of stacked three port circulators each having a respective first port of a first port array, a respective second port of a second port array, and a respective third port of a third port array. Each of the plurality of staked three port circulators share optical components including a first micro lens array optically coupled to the first port array and the third port array, a first walk off crystal, a first half wave plate, a first faraday rotator, a first birefringence wedge pair, a second birefringence wedge pair, a second Faraday rotator, a second half wave plate, a second birefringence walk off crystal, and a second micro lens array optically coupled to the second port array.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for optical communications. In one aspect, an optical circulator array includes a plurality of stacked three port circulators each having a respective first port of a first port array, a respective second port of a second port array, and a respective third port of a third port array, wherein each of the plurality of stacked three port circulators share optical components including: a first Wollaston prism coupled to the first port array, a first lens, a first half wave plate, a polarization dependent beam path separator, a second half wave plate, a second lens, a propagation direction dependent polarization rotation assembly, a second Wollaston prism coupled to the second port array, and a third Wollaston prism coupled to the third port array.

Abstract: Methods, systems, and apparatus for optical wavelength selective switching. One 2×2 wavelength selective switch array includes a plurality of optical input ports configured to receive one or more optical input beams, and a plurality of optical output ports configured to receive one or more one or more optical output beams wherein the plurality of optical input ports and optical output ports form an array of 2×2 optical port pairs; one or more optical conditioning and wavelength dispersion elements; a polarization modulator array having a plurality of polarizing modulation cells, each cell configured to independently change a polarization orientation of an optical beam passing through the cell and associated with a particular wavelength channel; and a polarization-selective beam-routing optical element configured to route each particular input beam to either a first output port or a second output port according to polarization orientation.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for optical communications. One optical amplifier includes an input port; a bar-cross switch optically coupled to the input port; a first gain stage optically coupled between first port of the bar-cross switch and to an output port; and a secondary gain stage optically coupled between a second port and a third port of the bar-cross switch, wherein in a bar-state of the bar-cross switch the secondary gain stage is bypassed and in a cross-state, the secondary gain stage and the first gain stage are applied to an input light beam.

Abstract: Methods, systems, and apparatus for optical wavelength selective switching. One 2×2 wavelength selective switch array includes a plurality of optical input ports configured to receive one or more optical input beams, and a plurality of optical output ports configured to receive one or more one or more optical output beams wherein the plurality of optical input ports and optical output ports form an array of 2×2 optical port pairs; one or more optical conditioning and wavelength dispersion elements; a polarization modulator array having a plurality of polarizing modulation cells, each cell configured to independently change a polarization orientation of an optical beam passing through the cell and associated with a particular wavelength channel; and a polarization-selective beam-routing optical element configured to route each particular input beam to either a first output port or a second output port according to polarization orientation.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for optical switching. An optical switch device includes a first multicast switch unit; and a second multicast switch unit, wherein each of the first and second multicast switch units respectively include: multiple optical input ports; multiple optical switches; multiple optical splitters/combiners; and multiple optical output ports.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for optical communications. In one aspect, an optical circulator array includes a plurality of stacked three port circulators each having a respective first port of a first port array, a respective second port of a second port array, and a respective third port of a third port array, wherein each of the plurality of staked three port circulators share optical components including: a first Wollaston prism coupled to the first port array, a first lens, a first half wave plate, a polarization dependent beam path separator, a second half wave plate, a second lens, a propagation direction dependent polarization rotation assembly, a second Wollaston prism coupled to the second port array, and a third Wollaston prism coupled to the third port array.

Abstract: Methods, systems, and apparatus, for optical communications. One apparatus includes a plurality of ingress ports coupled to N units of 1×n splitters, wherein each 1×n splitter includes a plurality of cross connect ingress branches and a drop branch; a plurality of egress ports coupled to N units of n×1 combiners, wherein each n×1 combiner includes a plurality of cross connect egress branches and an add branch; a M×M? fiber shuffle providing cross connect between the ingress branches and the egress branches such that each branch from an ingress 1×n splitter is linked to a branch of each n×1 combiner; and a wavelength blocker array comprising N×n wavelength blocker units where n?N wavelength blocker units, each wavelength blocker unit coupled to a fiber of the M×M? fiber shuffle.

Abstract: Methods, systems, and apparatus for optical wavelength selective switching. One 2×2 wavelength selective switch array includes a plurality of optical input ports configured to receive one or more optical input beams, and a plurality of optical output ports configured to receive one or more one or more optical output beams wherein the plurality of optical input ports and optical output ports form an array of 2×2 optical port pairs; one or more optical conditioning and wavelength dispersion elements; a polarization modulator array having a plurality of polarizing modulation cells, each cell configured to independently change a polarization orientation of an optical beam passing through the cell and associated with a particular wavelength channel; and a polarization-selective beam-routing optical element configured to route each particular input beam to either a first output port or a second output port according to polarization orientation.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for optical communications. One optical amplifier includes an input port; a bar-cross switch optically coupled to the input port; a first gain stage optically coupled between first port of the bar-cross switch and to an output port; and a secondary gain stage optically coupled between a second port and a third port of the bar-cross switch, wherein in a bar-state of the bar-cross switch the secondary gain stage is bypassed and in a cross-state, the secondary gain stage and the first gain stage are applied to an input light beam.

Abstract: Methods, systems, and apparatus, for optical switching. In one aspect, a wavelength selective switch includes one or more optical input ports; one or more optical output ports; a first optical wavelength dispersion element configured to separate the plurality of wavelength channels of the input optical beam; a second optical wavelength dispersion element configured to combine two or more separate optical beams each having one or more different wavelengths, into a combined beam having the plurality of wavelength channels; a polarization modulator array configured to independently change a polarization orientation of an optical beam passing through; optical components for directing optical beams corresponding to respective wavelength channels to different polarizing modulation cells; and a polarization beam splitter configured to route received optical beams to particular output paths according to polarization orientation.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for optical switching. An optical switch device includes a first multicast switch unit; and a second multicast switch unit, wherein each of the first and second multicast switch units respectively include: multiple optical input ports; multiple optical switches; multiple optical splitters/combiners; and multiple optical output ports.

Abstract: Methods, systems, and apparatus, for optical switching. In one aspect, a wavelength selective switch includes one or more optical input ports; one or more optical output ports; a first optical wavelength dispersion element configured to separate the plurality of wavelength channels of the input optical beam; a second optical wavelength dispersion element configured to combine two or more separate optical beams each having one or more different wavelengths, into a combined beam having the plurality of wavelength channels; a polarization modulator array configured to independently change a polarization orientation of an optical beam passing through; optical components for directing optical beams corresponding to respective wavelength channels to different polarizing modulation cells; and a polarization beam splitter configured to route received optical beams to particular output paths according to polarization orientation.

Abstract: A tunable filter array comprises a serial of tunable filters each has an input optical port and at least two output optical ports. All of the tunable filters commonly share a polarization conditioning optics, a polarization selective beam routing optics, a wavelength selective beam spatial separation/combination optics and a polarization controlling element array. The serial tunable filters are packaged by vertically stacking multiple sets of the input and output optical ports. The wavelength dependent beam separation/combination optics disperses an input optical beam into a two dimensional array of beam spots to focus on the two dimensional polarization control element array for controlling the polarization states of each of the beam spots. The polarization selective beam routing optics selectively routes the reflected beam from the wavelength dependent beam separation/combination optics to the output optical ports according to the polarization states of a wavelength segment corresponding to the beam spots.