An embodiment of the invention relates to an optical assembly comprising an optical emitter configured to generate a beam of optical radiation, a cap unit holding the optical emitter, a photonic chip comprising a coupler, and an intermediate chip arranged between the cap unit and the photonic chip, wherein the cap unit comprises a recess having a bottom section and a sidewall, wherein the optical emitter is mounted on the bottom section of the recess, wherein a section of the sidewall forms a mirror section angled with respect to the bottom section and configured to reflect said beam of optical radiation towards the coupler, and wherein the intermediate chip comprises a lens formed at a lens section of the intermediate chip's surface that faces the cap unit, said lens being configured to focus the reflected optical beam towards the coupler.

There is provided an optical system for coupling light into a waveguide. The optical system comprising a coupler arranged at a portion of the waveguide. The coupler has a surface with a grating structure for directing light into the waveguide formed therein. A cladding layer embeds the coupler and an optical path changing structure is formed in the cladding layer. The optical path changing structure has a refractive surface and a reflective surface, each forming an acute angle with respect to the surface of the coupler. Light which enters the optical path changing structure through the refractive surface will be refracted and directed towards the reflective surface. The reflective surface is arranged to reflect the light such that it is directed towards the grating structure of the coupler along a direction suitable for efficient coupling of light into the waveguide.

In an example, an Echelle grating wavelength division multiplexing (WDM) device includes a first waveguide, a slab waveguide, multiple second waveguides, an Echelle grating, and a metal-filled trench. The first waveguide includes either an input waveguide or an output waveguide. The multiple second waveguides are optically coupled to the first waveguide through the slab waveguide. The multiple second waveguides include multiple output waveguides if the first waveguide includes the input waveguide or multiple input waveguides if the first waveguide includes the output waveguide. The Echelle grating includes multiple grating teeth formed in the slab waveguide. The metal-filled trench forms a mirror at the grating teeth to reflect incident light from the first waveguide toward the multiple second waveguides or from the multiple second waveguides toward the first waveguide.

In an example, an Echelle grating wavelength division multiplexing (WDM) device includes a first waveguide, a slab waveguide, multiple second waveguides, an Echelle grating, and a metal-filled trench. The first waveguide includes either an input waveguide or an output waveguide. The multiple second waveguides are optically coupled to the first waveguide through the slab waveguide. The multiple second waveguides include multiple output waveguides if the first waveguide includes the input waveguide or multiple input waveguides if the first waveguide includes the output waveguide. The Echelle grating includes multiple grating teeth formed in the slab waveguide. The metal-filled trench forms a mirror at the grating teeth to reflect incident light from the first waveguide toward the multiple second waveguides or from the multiple second waveguides toward the first waveguide.

A structure for coupling an optical signal between an integrated circuit photonic structure and an external optical fiber is disclosed as in a method of formation. The coupling structure is sloped relative to a horizontal surface of the photonic structure such that light entering or leaving the photonic structure is substantially normal to its upper surface.

A structure for coupling an optical signal between an integrated circuit photonic structure and an external optical fiber is disclosed as in a method of formation. The coupling structure is sloped relative to a horizontal surface of the photonic structure such that light entering or leaving the photonic structure is substantially normal to its upper surface.

A waveguide having a gradient-index (GRIN) waveguide lateral coupler is provided. In an example embodiment, the waveguide comprises an active region. The refractive index profile of the active region is non-constant.

Methods and systems for optoelectronics transceivers of a CMOS chip are disclosed and may include receiving optical signals from optical fibers via grating couplers, which may include a guard ring. A CW optical signal may be received from a laser source via optical couplers, and may be modulated using optical modulators, which may be Mach-Zehnder and/or ring modulators. Circuitry in the CMOS chip may drive the optical modulators. The modulated optical signal may be communicated out of the CMOS chip into optical fibers via grating couplers. The received optical signals may be communicated between devices via waveguides. The photodetectors may include germanium waveguide photodiodes, avalanche photodiodes, and/or heterojunction diodes. The CW optical signal may be generated using an edge-emitting and/or a vertical-cavity surface emitting semiconductor laser.

Methods and systems for optoelectronics transceivers of a CMOS chip are disclosed and may include receiving optical signals from optical fibers via grating couplers, which may include a guard ring. A CW optical signal may be received from a laser source via optical couplers, and may be modulated using optical modulators, which may be Mach-Zehnder and/or ring modulators. Circuitry in the CMOS chip may drive the optical modulators. The modulated optical signal may be communicated out of the CMOS chip into optical fibers via grating couplers. The received optical signals may be communicated between devices via waveguides. The photodetectors may include germanium waveguide photodiodes, avalanche photodiodes, and/or heterojunction diodes. The CW optical signal may be generated using an edge-emitting and/or a vertical-cavity surface emitting semiconductor laser.

To provide a multiplexer that makes it possible to achieve a reduction in size and that minimizes the influence of the expansion of laser light on a multiplexing unit. A multiplexer is provided with a plurality of waveguides, multiplexing units that are provided at an intermediate location within the waveguides, and laser light sources, wherein: the first multiplexing unit is arranged at a position that is closest to the laser light sources; and the laser light sources that have an optical axis at a position that is separated from the transmission axis of the visible light that is introduced into the first multiplexing unit are arranged so that the optical axis is inclined with respect to the transmission axis and the outer periphery of laser light that expands at a predetermined expansion angle passes in front of the first multiplexing unit.