Abstract: The present disclosure provides a dither-free bias control of an optical modulator (OM) for the externally-modulated transmitter with the silicon-based Mach-Zehnder modulator (MZM), while the nonlinear distortions (NLDs) are generated by the plasma dispersion effect of the silicon-based MZM. The present disclosure proposes to intentionally offset the bias point of the MZM from its quadrature points, and therefore the Mach-Zehnder interference (MZI)-induced even-order NLDs can be generated to cancel the plasma dispersion-induced even-order NLDs. In addition, the MZM bias control is also proposed to arbitrarily adjust and lock in the bias point of an OM so a transmitter with the integrated MZM may reach the best even-order NLDs by offsetting from the quadrature points. Moreover, while the proposed scheme could arbitrarily adjust and lock in the bias of MZM, the receiver sensitivity may be optimized by using such a bias control scheme to adjust the extinction ratio of multi-level signals.

Abstract: An optical amplifier includes an input port for receiving an input optical signal;a wavelength division multiplexer (204) having a first input coupled to the input port, a second input coupled to a pump source (206), and an output coupled to an amplification fiber (208); and an integrated component (210) configured to provide output monitoring and isolation, wherein the integrated component (210) is configured to separate a first portion of a light signal received from the amplification fiber (208), direct the first portion to a photo detector, direct a second portion of the input light from the amplification fiber (208) to an output port, and attenuate light signals received from the output port.

Abstract: The present disclosure provides an optical fiber receptacle, an optical fiber connection device and an optical fiber receptacle module. The optical fiber receptacle comprises a housing, a plurality of positioning hooks and at least one clamping unit. The housing has a rear wall, and at least one slot opened on an opposite side of the rear wall. The rear wall has an inner surface facing the slot and an outer surface opposite to the inner surface, the slot is used to be inserted by an optical fiber plug. The positioning hook protrudes from the outer surface of the rear wall in a column shape, is used to pass through a mounting hole of a panel to latched with a hole edge defining the mounting hole of the panel.

Abstract: Methods, systems, and apparatus, for an external cavity FP laser. In one aspect, an apparatus is provided that includes a FP laser diode; a Faraday rotator (FR) coupled to receive an optical output of the FP laser diode and that rotates a polarization of the optical output; an optical fiber coupled at a first end to receive the output of the FR; a WDM filter coupled to a second end of the optical fiber to receive the optical signal from the optical fiber; and a FRM coupled directly or indirectly to an output of the WDM filter, wherein an optical output of the WDM filter is partially reflected by the FRM such that the polarization of a reflected beam is rotated, and wherein the reflected optical signal then passes through the FR with its polarization being rotated by the FR before it is injected back into the FP laser diode.

Abstract: Methods, systems, and apparatus, for optical depolarization. One optical depolarizer includes a light-combining module comprising a birefringent prism, wherein an optic axis of a first crystal of the birefringent prism forms a 90° angle with an optic axis of a second crystal of the birefringent prism; and a depolarization module, wherein the depolarization module is disposed at a light emitting end of the light-combining module, the depolarization module comprising a light splitting component and a light-combining component disposed at an emitting end of the light-splitting component, and a delayer disposed between the light-splitting component and the light-combining component, wherein the delayer is disposed on an emitting optical path of the light-splitting component.

Abstract: Systems, methods, and apparatus for optical switching. In some implementations, a magneto-optic switch includes multiple optical components positioned in order along a light path including: a single fiber optical collimator, a first birefringent optic crystal, a first half wave plate assembly, a polarization rotation assembly, a second half wave plate assembly, a second birefringent optic crystal, and a dual fiber optic collimator, wherein a first side of the polarization rotation assembly near the first half wave plate assembly includes a first Faraday rotator element, a second side of the polarization rotation assembly near the second half wave plate assembly includes an optic rotation component, the polarization rotation assembly having a magnetic field generating component outside the first Faraday rotator element.

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 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 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 amplifier includes an input port, a wavelength division multiplexing fiber coupled to a pump source and to a bar-cross switch, a first gain stage optically coupled between a first port of the bar-cross switch and to an output port, the first gain stage including a first gain flattening filter, and a secondary gain stage optically coupled between a second port and a third port of the bar-cross switch, the secondary gain stage including a second gain flattening filter. When in a bar-state of the bar-cross switch, the secondary gain stage is bypassed. And when in a cross-state of the bar-cross switch, the secondary gain stage and the first gain stage are applied to an input light beam.

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 communication. One apparatus includes a Fabry-Perot (FP) laser diode assembly coupled to a first port of a circulator; an optical amplifier coupled to a second port of the circulator; a wavelength division multiplexer (WDM) filter coupled to a third port of the circulator; and a Faraday rotator mirror coupled to the WDM filter.

Abstract: Methods, systems, and apparatus, for an external cavity FP laser. In one aspect, an apparatus is provided that includes a FP laser diode; a Faraday rotator (FR) coupled to receive an optical output of the FP laser diode and that rotates a polarization of the optical output; an optical fiber coupled at a first end to receive the output of the FR; a WDM filter coupled to a second end of the optical fiber to receive the optical signal from the optical fiber; and a FRM coupled directly or indirectly to an output of the WDM filter, wherein an optical output of the WDM filter is partially reflected by the FRM such that the polarization of a reflected beam is rotated, and wherein the reflected optical signal then passes through the FR with its polarization being rotated by the FR before it is injected back into the FP laser diode.

Abstract: Methods, systems, and apparatus for optical communications. One of the apparatuses includes a spool comprising a spool wheel, one or more separate spool portions positioned on the spool wheel, and one or more bearings positioned on the spool wheel, wherein the one or more spool portions and the one or more bearings are configured such that an optical fiber ribbon can be wound through the spool; and a spring coupled to the spool wheel such that the spring provides a rotational force on the spool in a direction that winds the optical fiber ribbon.

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 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 an external cavity FP laser. In one aspect, an apparatus is provided that includes a FP laser diode; a Faraday rotator (FR) coupled to receive an optical output of the FP laser diode and that rotates a polarization of the optical output; an optical fiber coupled at a first end to receive the output of the FR; a WDM filter coupled to a second end of the optical fiber to receive the optical signal from the optical fiber; and a FRM coupled directly or indirectly to an output of the WDM filter, wherein an optical output of the WDM filter is partially reflected by the FRM such that the polarization of a reflected beam is rotated, and wherein the reflected optical signal then passes through the FR with its polarization being rotated by the FR before it is injected back into the FP laser diode.