A demultiplexer for use in a wavelength division multiplexed system. The demultiplexer comprises: an input waveguide, configured to receive a wavelength division multiplexed signal; a demultiplexing element, configured to demultiplex the multiplexed signal received from the input waveguide into a plurality of multi-mode demultiplexed signal components; a multi-mode output waveguide, the multi-mode output waveguide being coupled to the demultiplexing element and configured to receive one of the multi-mode demultiplexed signal components; and a splitter, coupled to the multi-mode output waveguide, and configured to split the received multi-mode demultiplexed signal component into two single-mode outputs.

An arrayed waveguide grating multiplexer/demultiplexer includes an array of optical waveguides ordered in sequence from a shortest waveguide up to a longest waveguide, and identical phase shifters configured to be controlled by a same control signal. Each phase shifter increases/decreases an optical path of an optical waveguide by the same quantity based on the control signal.

The wavelength response of an arrayed waveguide grating can be tuned, in accordance with various embodiments, using a beam sweeper including one or more heaters to shift a lateral position of light focused by the beam sweeper at an interface of the beam sweeper with an input free propagation region of the arrayed waveguide grating.

A device includes a substrate, a dielectric layer on the substrate, a waveguide within the dielectric layer, and a photodetector optically coupled to the waveguide. The photodetector is disposed above the waveguide layer and is monolithically integrated with the substrate. The photodetector is configured to operate at low temperatures, such as below about 50 K or about 20 K. In some embodiments, the monolithic photonic device includes thermal isolation structures and optical isolation structures. Techniques for manufacturing the monolithic photonic device, including the thermal isolation structures and optical isolation structures, are also described.

The present disclosure provides a calibration system for wavelength-division multiplexing (WDM), a WDM system, and a calibrating method for WDM. The calibration system includes heating devices, an optical sensor, and an electrical device. When the optical sensor receives no beam with energy exceeding a threshold value from a first channel, the optical sensor transmits a first signal to the electrical device. In response to the first signal, the electrical device is configured to control the one or more of the heating devices to heat one or more of channels. When the optical sensor receives a beam having energy exceeding the threshold value from the first channel, the optical sensor transmits a second signal to the electrical device. In response to the second signal, the electrical device is configured to control the one or more of the heating devices to maintain the temperature of the one or more of the channels.

A thermal compensator, for use in connection with arrayed waveguide grating (AWG) modules which are, in turn, utilized in conjunction with wavelength multiplexing and de-multiplexing within optical networks, is disclosed. The thermal compensator comprises a bow-shaped frame member and a central bar member. The bow-shaped frame member is characterized by a higher coefficient of thermal expansion than that of the central bar member such that the bow-shaped frame member can expand and contract at variable rates compared to that of the central bar member under certain temperature conditions. The bow-shaped frame member is adapted to be attached to a movable section of an athermal arrayed waveguide grating (AAWG) module such that the expansion and contraction movements of the bow-shaped member influence the movement of a movable section of the AAWG module in order to maintain the proper focus of the AAWG module across disparate temperature conditions.

The present disclosure provides a calibration system for wavelength-division multiplexing (WDM), a WDM system, and a calibrating method for WDM. The calibration system includes heating devices, an optical sensor, and an electrical device. When the optical sensor receives no beam with energy exceeding a threshold value from a first channel, the optical sensor transmits a first signal to the electrical device. In response to the first signal, the electrical device is configured to control the one or more of the heating devices to heat one or more of channels. When the optical sensor receives a beam having energy exceeding the threshold value from the first channel, the optical sensor transmits a second signal to the electrical device. In response to the second signal, the electrical device is configured to control the one or more of the heating devices to maintain the temperature of the one or more of the channels.

An arrayed waveguide grating device includes an input coupler configured to receive a light signal and split the light signal into a plurality of output light signals. The device also includes a plurality of waveguides optically connected to the input coupler, each waveguide having a plurality of waveguide portions having respective sensitivities to variance in one or more parameters associated with operating of the optical arrayed grating device. Lengths of the respective portions are determined such that each waveguide applies a respective phase shift to the output light signal that propagates through the waveguide and the plurality of waveguides have at least substantially same change in phase shift with respective changes in the one or more parameters associated with operation of the device. An output coupler is optically connected to the plurality of waveguides to map respective light signals output from the plurality of waveguides to respective focal positions.

Athermal arrayed waveguide grating structure that may operate as an optical filter including an input Silicon (Si) slab waveguide, an output Si slab waveguide, the input Si slab waveguide and the output Si slab waveguide optically connected by an arrayed group of Silicon Nitride (SiN) grating waveguides. Temperature insensitivity of the structure is achieved by locating output waveguide(s) of the Si output slab waveguide at/within a 10-degree angle offset from the center line of the output Si slab waveguide.

An arrayed waveguide grating device includes an input coupler configured to receive a light signal and split the light signal into a plurality of output light signals. The device also includes a plurality of waveguides optically connected to the input coupler, each waveguide having a plurality of waveguide portions having respective sensitivities to variance in one or more parameters associated with operating of the optical arrayed grating device. Lengths of the respective portions are determined such that each waveguide applies a respective phase shift to the output light signal that propagates through the waveguide and the plurality of waveguides have at least substantially same change in phase shift with respective changes in the one or more parameters associated with operation of the device. An output coupler is optically connected to the plurality of waveguides to map respective light signals output from the plurality of waveguides to respective focal positions.