A device, such as an electroabsorption modulator, can modulate a light intensity by controllably absorbing a selectable fraction of the light. The device can include a substrate. A waveguide positioned on the substrate can guide light. An active region positioned on the waveguide can receive guided light from the waveguide, absorb a fraction of the received light, and return a complementary fraction of the received light to the waveguide. Such absorption produces heat, mostly at an input portion of the active region. The input portion of the active region can be thermally coupled to the substrate, which can dissipate heat from the input portion, and can help avoid thermal runaway of the device. The active region can be thermally isolated from the substrate away from the input portion, which can maintain a relatively low thermal mass for the active region, and can increase efficiency when heating the active region.

A method of manufacturing a semiconductor structure comprising: depositing a first layer in contact with a first surface area of a substrate; depositing a second layer in contact with a second surface area of the substrate, the second surface area substantially co-planar with and outwards of the first surface area; depositing a third layer in contact with the first layer and the second layer; removing a portion of the third layer to expose a portion of the first layer; and removing at least a portion of the first layer to create a cavity between the substrate, the second layer and the third layer.

An optical transmission device includes a semiconductor laser chip in which a semiconductor laser array having a plurality of distributed feedback semiconductor lasers formed on a first semiconductor substrate is formed, a semiconductor waveguide chip in which a semiconductor modulator array formed on a second semiconductor substrate and having the same number of semiconductor modulators as the semiconductor lasers is formed. In the optical transmission device, a waveguide and a waveguide are butt-joined such that a distance between an end face of the waveguide on a side to the semiconductor modulator array in each of the semiconductor lasers of the semiconductor laser array and an end face of the waveguide on a side to the semiconductor laser array in each of the semiconductor modulators of the semiconductor modulator array is 10 μm or less.

A semiconductor layer formed on a clad layer and a light absorbing layer formed on the semiconductor layer are provided. The semiconductor layer includes a p-type region and an n-type region. The p-type region, which is of p-type, is provided on a side of one side portion of the light absorbing layer in a direction perpendicular to a direction in which light is guided, and the n-type region, which is of n-type, is provided on a side of another side portion of the light absorbing layer in the direction perpendicular to the direction in which light is guided. A p-type contact layer, which is of p-type, is formed on the p-type region, and an n-type contact layer is formed on the n-type region.

Structures and methods for passively aligning a photonic die with a receiving substrate are described. Three alignment surfaces, having dimensions greater than a desired alignment accuracy, may be formed on the photonic die and used to passively and accurately align the photonic die to a receiving substrate in six degrees of freedom. Two of the three alignment surfaces on the photonic die may be formed in a single mask-and-etch process, while the third alignment surface may require no patterning or etching. Three complementary alignment surfaces on the receiving substrate may be formed in a single mask-and-etch process.

A beam steering apparatus includes a substrate; at least one light source provided on the substrate; a first waveguide configured to transmit a first light beam radiated from the at least one light source; at least one beam splitter configured to split the first light beam transmitted by the first waveguide to obtain a second light beam; a second waveguide configured to receive the second light beam; and a quantum dot optical amplifier provided on the second waveguide and comprising a barrier layer, a quantum dot layer, and a wetting layer, the quantum dot optical amplifier being configured to modulate a phase of the second light beam, and to amplify an intensity of the second light beam.

A method of manufacturing a semiconductor optical device includes a step of bonding a semiconductor element to a substrate that includes silicon, the semiconductor element being made of a III-V compound semiconductor and having optical gain; after the step of bonding the semiconductor element, a step of molding the semiconductor element by wet-etching; and after the step of molding the semiconductor element, a step of forming a mesa at the semiconductor element. The substrate includes a waveguide, a groove that extends along the waveguide, a terrace that is positioned on a side of the groove opposite to the waveguide, and a wall that covers the groove. The step of bonding the semiconductor element is a step of bonding the semiconductor element to the waveguide, the groove, the terrace, and the wall of the substrate.

A first photonic die has a first coupling edge and a first die surface, and comprises: a first waveguide extending in proximity to the first coupling edge; a portion of the first die surface forming an alignment edge substantially parallel to the first waveguide; and a first alignment feature etched into or formed adjacent to the first coupling edge. A second photonic die has a second coupling edge and a second die surface, and comprises: a second waveguide extending in proximity to the second coupling edge; a portion of the second die surface configured to form a receptacle sized to constrain a position of the alignment edge; and a second alignment feature etched into or formed adjacent to the second coupling edge and configured to enable alignment with the first alignment feature when the first photonic die and the second photonic die are substantially aligned with each other.

A first photonic die has a first coupling edge and a first die surface, and comprises: a first waveguide extending in proximity to the first coupling edge; a portion of the first die surface forming an alignment edge substantially parallel to the first waveguide; and a first alignment feature etched into or formed adjacent to the first coupling edge. A second photonic die has a second coupling edge and a second die surface, and comprises: a second waveguide extending in proximity to the second coupling edge; a portion of the second die surface configured to form a receptacle sized to constrain a position of the alignment edge; and a second alignment feature etched into or formed adjacent to the second coupling edge and configured to enable alignment with the first alignment feature when the first photonic die and the second photonic die are substantially aligned with each other.

Optical beam forming at the inputs/outputs of a photonic chip and to the spectral broadening of the light coupled to the chip. The photonic chip comprises an optical waveguide layer supported on a substrate. The chip includes an optical waveguide structure made of silicon and a coupling surface grating. The photonic chip has a front face on the side facing the coupling surface grating and a rear face on the side facing the substrate. A reflecting collimation structure is integrated in the rear face to modify the mode size of an incident light beam. The coupling surface grating is designed to receive light from the optical waveguide structure and to form a light beam directed to the reflecting collimation structure. The invention further relates to the method for producing such a chip.