An athermal arrayed waveguide grating includes a silicon-based substrate and an athermal arrayed waveguide disposed on the silicon-based substrate. The athermal arrayed waveguide includes a cladding layer and a waveguide chip layer, the waveguide chip layer is disposed on the cladding layer and has a refractive index greater than that of the cladding layer; the waveguide core layer includes multilayer structures having a periodic configuration, the multilayer structure includes two layers of silica material and a negative temperature coefficient material disposed between the two layers of silica material; the negative temperature coefficient material is used to compensate for a dimensional deformation of the silicon-based substrate after being heated. The present invention simplifies the structure of the athermal arrayed waveguide grating, sets the negative temperature coefficient material in the waveguide core layer structure, and makes the final temperature coefficient of refractive index of the waveguide structure is a negative number.

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.

Disclosed is a thermal stabilization circuit including a heater, which is adjacent and thermally coupled to a closed-curve waveguide of an optical ring resonator, and an analog feedback circuit, which includes a fully autonomous analog feedback loop from a drop port of a bus waveguide of the optical ring resonator to the heater. This analog feedback circuit is configured to dynamically control the electrical power provided to the heater and, thereby to dynamically control the thermal output of the heater in order to tune the ring resonance wavelength to the operating laser wavelength. The analog feedback circuit is further configured to be independent of input power, to be power efficient, to have a relatively small footprint, to have a tunable time constant and to facilitate adjustable wavelength locking. Also disclosed is a device (e.g., a ring-based transceiver or the like), which includes multiple optical ring resonators and corresponding thermal stabilization circuits.

An athermal arrayed waveguide grating includes a silicon-based substrate and an athermal arrayed waveguide disposed on the silicon-based substrate. The athermal arrayed waveguide includes a cladding layer and a waveguide chip layer, the waveguide chip layer is disposed on the cladding layer and has a refractive index greater than that of the cladding layer; the waveguide core layer includes multilayer structures having a periodic configuration, the multilayer structure includes two layers of silica material and a negative temperature coefficient material disposed between the two layers of silica material; the negative temperature coefficient material is used to compensate for a dimensional deformation of the silicon-based substrate after being heated. The present invention simplifies the structure of the athermal arrayed waveguide grating, sets the negative temperature coefficient material in the waveguide core layer structure, and makes the final temperature coefficient of refractive index of the waveguide structure is a negative number.

Aspects of the present disclosure are directed to wavelength division multiplexing systems comprising arrays of spectrally selective devices that are arranged on a substrate to compensate for perturbations of the spectral characteristics of the devices due to factors such as temperature non-uniformity, inherent spectral non-uniformity, and the like. As a result, shifts in the center wavelengths and/or changes in the wavelength spacing for the wavelength channels of a WDM system due to such perturbations are mitigated. In some embodiments, an array of spectrally selective devices is arranged on a substrate such that their respective wavelength channels are not linearly correlated with their physical position within the array, enabling the devices to be arranged in pairs that are subject to substantially the same environmental conditions and/or operate on nearly the same spectral range.

Thermally compensated waveguides are disclosed herein. According to one aspect, the present disclosure proposes new ways to combine negative TOC (NTOC) material layers within the waveguides. NTOC materials can be implemented in one or more of a cladding layer, a core rib/channel waveguide, a horizontally segmented waveguide, a vertically segmented waveguide, a sub-wavelength grating structure, and/or in various other waveguide structure implementations including arbitrary core or cladding shapes. The integration of NTOC materials improves the temperature dependence of the waveguide spectrum. The need for fast and efficient optical-based technologies is increasing as Internet data traffic growth rate is overtaking voice traffic, pushing the need for optical communications. The new waveguide structures can be integrated into waveguides, individual devices, integrated devices like arrayed waveguide grating devices, and photonic integration circuits (PICs), decreasing temperature dependence of such devices and circuits.

Photonic integrated circuits utilizing interferometric effects, such as wavelength multiplexers/demultiplexers, include a free-space coupling region having two core layers that have thermo-optic coefficients of opposite sign. The two core layers are configured to provide athermal or nearly-athermal operation. Described examples include integrated array waveguide grating devices and integrated echelle grating devices. Example material systems include LNOI and SOI.

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.

Aspects of the present disclosure are directed to wavelength division multiplexing systems comprising arrays of spectrally selective devices that are arranged on a substrate to compensate for perturbations of the spectral characteristics of the devices due to factors such as temperature non-uniformity, inherent spectral non-uniformity, and the like. As a result, shifts in the center wavelengths and/or changes in the wavelength spacing for the wavelength channels of a WDM system due to such perturbations are mitigated. In some embodiments, an array of spectrally selective devices is arranged on a substrate such that their respective wavelength channels are not linearly correlated with their physical position within the array, enabling the devices to be arranged in pairs that are subject to substantially the same environmental conditions and/or operate on nearly the same spectral range.

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.