Abstract: Methods, systems, and apparatus for optical communications are provided. One of the apparatus includes a first Faraday rotator having an applied magnetic field in a first direction; a second Faraday rotator optically coupled to the first Faraday rotator, the second Faraday rotator having an applied magnetic field in a second direction in opposition to the first direction; and a mirror optically coupled to the second Faraday rotator.

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. 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 for optical communications. One of the apparatuses comprises a birefringent crystal configured to separate an incoming light beam input at a first port into component light beams having orthogonal polarization directions and directing the component light beams on respective paths to exit locations on the birefringent crystal; and a Faraday rotator positioned between the birefringent crystal and a beam folding optic assembly, wherein the Faraday rotator is positioned such that light beams exiting the birefringent crystal along a first path from a first exit location pass through the Faraday rotator before being incident on the beam folding optic assembly and that light beams exiting the birefringent crystal along a second path from a second exit location pass directly to the beam folding optic assembly without being incident on the Faraday rotator.

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, 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 are provided. One of the apparatus includes a first Faraday rotator having an applied magnetic field in a first direction; a second Faraday rotator optically coupled to the first Faraday rotator, the second Faraday rotator having an applied magnetic field in a second direction in opposition to the first direction; and a mirror optically coupled to the second Faraday rotator.

Abstract: Methods, systems, and apparatus for optical communications. One of the apparatuses comprises a birefringent crystal configured to separate an incoming light beam input at a first port into component light beams having orthogonal polarization directions and directing the component light beams on respective paths to exit locations on the birefringent crystal; and a Faraday rotator positioned between the birefringent crystal and a beam folding optic assembly, wherein the Faraday rotator is positioned such that light beams exiting the birefringent crystal along a first path from a first exit location pass through the Faraday rotator before being incident on the beam folding optic assembly and that light beams exiting the birefringent crystal along a second path from a second exit location pass directly to the beam folding optic assembly without being incident on the Faraday rotator.