An implantable optical sensor (1) comprising a substrate (2) and at least one optical microstructure (3) for evanescent field sensing integrated with the substrate (2), the at least one optical microstructure (3) being positioned to form an optical interaction area (4) on a part of a surface (5) of the substrate (2), the optical assembly (1) further comprising a thin protective layer (6) covering at least the optical interaction area (4), the thin protective layer (6) being in a predetermined material with corrosion-protection characteristics and having a predetermined thickness, so as not to affect the evanescent field sensing.

A mode field adapter (MFA) is disclosed. The MFA is tapered and includes a passive core region and an active core region separated by a distance. Further, the passive core region includes first and second passive layers that are separated by another distance. The MFA is configured to receive an optical signal from a first waveguide, and alter, for transmission to a second waveguide, an optical mode of the optical signal. The optical mode is altered based on the distance between the first and second passive layers, the distance between the active and passive core regions, and the tapering of the MFA. The optical mode is altered such that an optical loss associated with the optical signal traversing from the first waveguide to the second waveguide by way of the MFA is within a tolerance limit.

There is provided a method for fabricating a vertically tapered spot-size converter on a substrate, comprising: growing a waveguide core on the substrate; coating the waveguide core with a photoresist layer; placing a photomask having patterns at a negative focus offset point with respect to the photoresist layer, the patterns being defined by openings in the photomask, each opening having a cross-section comprising a region of constant width and at least one region of non-constant width, the non-constant width reducing in a direction extending away from the region of constant width; transferring the patterns of the photomask to the photoresist layer; providing the waveguide core with a vertically tapered profile, the vertically tapered profile being provided by the patterns of the photomask; growing a cladding layer over the waveguide core; and patterning and etching the cladding layer and the waveguide core, thereby defining the vertically tapered spot-size converter.

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 light receiving device includes, on a substrate, a Si waveguide core provided in a dielectric layer, a first i-type waveguide clad, an i-type core layer, a second i-type waveguide clad, p-type layers disposed on one side of a side surface of a layered structure in a light waveguide direction, the layered structure including the first i-type waveguide clad, the i-type core layer, and the second i-type waveguide clad, n-type layers disposed on the other side, and an electrode on a surface of each of the n-type layers. A width of the Si waveguide core is set to be able to suppress absorption of light in a vicinity of an input edge of the i-type core layer.

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 light reception device of the present invention includes a first i-type cladding region, an n-type waveguide core having a predetermined width, and a second i-type cladding region in contact with a side surface of the n-type waveguide core on a substrate, includes a p-type absorption layer, a p-type diffusion barrier layer, a p-type contact layer, and a p-type electrode formed in an upper part above a region including a part of the n-type waveguide core, with an i-type insertion layer interposed between the upper part and the region, and includes an n-type electrode on an upper surface of another part of the n-type waveguide core.

Silicon photonic integrated circuit (PIC) on a multi-zone semiconductor on insulator (SOI) substrate having at least a first zone and a second zone. Various optical devices of the PIC may be located above certain substrate zones that are most suitable. A first length of a photonic waveguide structure comprises the crystalline silicon and is within the first zone, while a second length of the waveguide structure is within the second zone. Within a first zone, the crystalline silicon layer is spaced apart from an underlying substrate material by a first thickness of dielectric material. Within the second zone, the crystalline silicon layer is spaced apart from the underlying substrate material by a second thickness of the dielectric material.

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.

A structure for a photonic integrated circuit, comprising: a substrate; a first portion of n-type semiconductor material on a first surface area of the substrate, a second portion of n-type semiconductor material on a second surface area of the substrate; a waveguide; and an element between the first portion and the second portion. The waveguide is on and in contact with the element. The element is configured to reduce electric current flow from the first portion to the second portion during propagation of light via the waveguide.