Abstract: An optical waveguide device, power coupler, a star coupler, a MMI coupler, an arrayed waveguide grating (AWG) or an Echelle grating, having at least one free space region with a plurality of optical waveguides coupled as inputs and separated by channels having a angled bottom portion, the channels monotonically decreasing in size or shape in a direction toward the free space region and optically coupling with adjacent waveguides at the interface region between the optical waveguides and the free space region so that insertion loss at the interface region is substantially reduced.

Abstract: A single monolithic transceiver chip for handling optical to electrical to optical conversion of optical WDM signals in an optical transmission network which has an optical WDM signal input for reception of a WDM signal and an optical WDM signal output for transmission of a WDM signal and a plurality of electrical signal outputs and a plurality of electrical signal inputs. The chip further comprises an integrated decombiner coupled to the optical signal input that separates the WDM signal into a plurality of separate optical channel signals, an integrated array of photodetectors that each receives a respective optical channel signal and that converts the optical channel signal into an electrical signal and that provides the converted electrical signals to the electrical signal outputs of the transceiver chip.

Abstract: An arrayed waveguide grating (AWG) comprises at least two free space regions, a plurality of grating arms extending between the two space regions, a passivation layer formed over the arrayed waveguide grating and a plurality of inputs at least to one of the free space regions to receive a plurality of channel signals separated by a predetermined channel spacing. A depth of the passivation layer chosen by providing a TE to TM wavelength shift between TE and TM modes propagating through the arrayed waveguide grating being approximately less than or equal to 20% of a magnitude of the channel spacing.

Abstract: A method for forming and apparatus comprising a free space coupler region having a plurality of optical waveguides coupled to the space coupler region at an interface region, the waveguides converging with one another to the interface region, and a trench formed between adjacent waveguides, the depth of the trench or trenches extending from an outer point to the interface region and monotonically decreasing in depth from the outer point to the interface region.

Abstract: A method of calibrating a monolithic transmitter photonic integrated circuit (TxPIC) chip is disclosed where the chip contains integrated arrays of laser sources and electro-optic modulators forming a plurality of different wavelength signal channels where each laser source on the chip is sequentially selected and tested for the output power and operational wavelength. Calibration data is initially determined by checking an amount of output power of each laser output and any offset of each laser operational wavelength from a desired predetermined value. Then, adjustment of the operational wavelength of each laser source is accomplished to substantially match the desired predetermined value. The laser source output power and operational wavelength may then be rechecked to determine if there is any remaining offset of each laser operational wavelength from the desired predetermined value.

Abstract: A method of in-wafer testing is provided for a monolithic photonic integrated circuit (PIC) formed in a semiconductor wafer where each such in-wafer circuit comprises two or more integrated electro-optic components, one of each in tandem forming a signal channel in the circuit. The method includes the provision of a first integrated photodetector at a rear end of each signal channel and a second integrated photodetector at forward end of each signal channel. Then, the testing is accomplished, first, by sequentially operating a first of a selected channel electro-optic component in a selected circuit to monitor light output from a channel via its first corresponding channel photodetector and adjusting its operating characteristics by detecting that channel electro-optic component output via its second corresponding channel photodetector to provide first calibration data.

Abstract: An on-chip photodiode is provided in a photonic integrated circuit (PIC) on a semiconductor chip to monitor or check for antireflection qualities of an AR coating applied to the front facet of the semiconductor chip.

Abstract: In photonic integrated circuits (PICs) having at least one active semiconductor device, such as, a buried heterostructure semiconductor laser, LED, modulator, photodiode, heterojunction bipolar transistor, field effect transistor or other active device, a plurality of semiconductor layers are formed on a substrate with one of the layers being an active region. A current channel is formed through this active region defined by current blocking layers formed on adjacent sides of a designated active region channel where the blocking layers substantially confine the current through the channel. The blocking layers are characterized by being an aluminum-containing Group III-V compound, i.e., an Al-III-V layer, intentionally doped with oxygen from an oxide source. Also, wet oxide process or a deposited oxide source may be used to laterally form a native oxide of the Al-III-V layer.

Abstract: A photonic integrated circuit (PIC) chip with a plurality of electro-optic components formed on a major surface of the chip and a submount that includes a substrate that extends over the major surface of the chip forming an air gap between the substrate and the major surface, the substrate to support electrical leads for electrical connection to some of the electro-optic components on the chip major surface.

Abstract: A method of operating an array of laser sources integrated as an array in a single monolithic chip where the steps include designing the laser sources to have different target emission wavelengths so that together they form a spectral emission wavelength grid, coupling outputs from the laser sources to an array of gain/loss elements also integrated on the single monolithic chip, one each receiving the output from a respective laser source; and adjusting the outputs with the gain/loss elements so that the power levels of the laser source array across are substantially uniform.

Abstract: A laser source or a plurality of laser sources in a photonic integrated circuit (PIC) are provided with an electrical contact that is either segmented or is connected to a series of vernier resistor segments for supply of current to operate the laser source. In either case, at least one segment of the laser contact or at least one vernier resistor segment can be trimmed in order to vary the amount of current supplied to the laser source resulting in a change to its current density and, thus, a change in its operational wavelength while maintaining the current supplied to the laser source constant.

Abstract: An optical probe and a method for testing an optical chip or device, such as an photonic integrated circuit (PIC), to provide for testing of such devices or circuits while they are still in their in-wafer form and is accomplished by using a an optical probe for interrogation of the circuit where an access is provided in the wafer to one or more of such in-wafer devices or circuits. As one example, the interrogation may be an interrogation beam provided at the access input to the in-wafer device or circuit. As another example, the interrogation may be an optical pickup from the access input to the in-wafer device or circuit.

Abstract: A method and apparatus operates an array of laser sources as an integrated array on a single substrate or as integrated in an optical transmitter photonic integrated circuit (TxPIC) maintaining the emission wavelengths of such integrated laser sources at their targeted emission wavelengths or at least to more approximate their desired respective emission wavelengths. Wavelength changing elements may accompany the laser sources to bring about the change in their operational or emission wavelength to be corrected to or toward the desired or target emission wavelength. The wavelength changing elements may be comprise of temperature changing elements, current and voltage changing elements or bandgap changing elements.

Abstract: A method of operating an array of integrated laser sources formed as an integrated array on a single substrate in a photonic integrated circuit (PIC) where the laser sources are designed for operation at different targeted emission wavelengths which, in toto, at least approximate a grid of spatial emission wavelengths. A first wavelength tuning element is associated with each laser source and is adjusted over time so that each laser source maintains its targeted emission wavelength. As an alternative, the drive current to each laser source may be initially set so that each laser source operates at its targeted emission wavelength. Thereafter, adjustments to retune the laser sources to their targeted emission wavelengths are accomplished by the first wavelength tuning elements. The outputs of the laser sources may be combined via an optical combiner to produce a single combined output from the PIC.

Abstract: A method of tuning optical components integrated on a monolithic chip, such as an optical transmitter photonic integrated circuit (TxPIC), is disclosed where a group of first optical components are each fabricated to have an operating wavelength approximating a wavelength on a standardized or predetermined wavelength grid and are each included with a local wavelength tuning component also integrated in the chip. Each of the first optical components is wavelength tuned through their local wavelength tuning component to achieve a closer wavelength response that approximates their wavelength on the wavelength grid.