An optical waveguide at least includes: a lower clad layer; a core that is disposed on the lower clad layer and includes an entrance plane and an emission plane; and an optical path converting mirror including an inclined surface that is neither in parallel with nor orthogonal to a plane formed by the lower clad layer. The core includes a restriction release plane. When one of two portions obtained by dividing the core in two at the restriction release plane that is on the side of the entrance plane is defined as a first core pattern portion and remaining one of the two portions on the side of the emission plane is defined as a second core pattern portion, the optical path converting mirror is disposed on an optical path of the first core pattern portion or an extension of the optical path. At least a part of the light that has entered through the entrance plane is reflected by the optical path converting mirror to have an optical path converted. At least a part of light with an optical path not converted to be in a substantially orthogonal direction is emitted from the emission plane.

Technologies for beam expansion and collimation for photonic integrated circuits (PICs) are disclosed. In one embodiment, an ancillary die is bonded to a PIC die. Vertical couplers in the PIC die direct light from waveguides to flat mirrors on a top side of the ancillary die. The flat mirrors reflect the light towards curved mirrors defined in the bottom surface of the ancillary die. The curved mirrors collimate the light from the waveguides. In another embodiment, a cavity is formed in a PIC die, and curved mirrors are formed in the cavity. Light beams from waveguides in the PIC die are directed to the curved mirrors, which collimate the light beams.

Technologies for coupling to and from a photonic integrated circuit (PIC) with an optical isolator are disclosed. In one embodiment, light beams from waveguides on a PIC die are reflected towards flat mirrors on the bottom surface of the PIC die. The flat mirrors reflect the light towards curved mirrors defined in a top surface of the PIC die, which collimate the beam and direct the collimated beams out the bottom surface of the PIC die. An optical isolator below the PIC die can allow the beams to pass while blocking beams in the opposite direction.

Example embodiments relate to multilayer integrated photonic structures. An example multilayer integrated photonic structure includes a propagation region formed in a first photonic layer. The propagation region includes a plurality of waveguides and a slab region in which the plurality of waveguides terminates. The multilayer integrated photonic structure also includes an outcoupling structure formed in a second photonic layer on top of the first photonic layer. The outcoupling structure is configured to couple light into and out of the multilayer integrated photonic structure. Additionally, the multilayer integrated photonic structure includes a reflector configured to optically couple the slab region of the first photonic layer and the second photonic layer. The reflector includes a first reflector element included in the slab region of the first photonic layer and a second reflector element included in the second photonic layer. The first and second reflector element are in optical communication with each other.

An integrated optical structure for multiplexing and/or demultiplexing an optical signal comprises a main waveguide having two parallel side surfaces, a first waveguide which meets the main waveguide at a first region on one of the two side surfaces, and a plurality of second waveguides which meet the main waveguide at a second region on one of the two side surfaces. The second region is spaced at a determined distance from the first region. The two side surfaces are arranged at a first angle relative to an extension direction of the first waveguide and a second angle relative to extension directions of the plurality of second waveguides. The optical structure further comprises one or more waveguide extension structures. Each waveguide extension structure is arranged adjacent to one of the two side surfaces of the main waveguide at a region that is different to the first and the second region.

A head-up display device includes a display element, a beam splitter, a movable mirror, first and second mirrors, and a movable unit. The display element emits light to form a display image. The beam splitter being an optical member that reflects light or through which light is transmitted, reflects light emitted from the display element. The movable mirror reflects light reflected off the beam splitter. The first and second mirrors that reflect light movable mirror, or through which the light transmitted through the beam splitter is transmitted, project a virtual image. The movable unit adjusts a distance between the movable mirror and the beam splitter to adjust a projection distance of the virtual image.

A connector for use in coupling an optical signal between an optical fiber in an optical plug mounted to a bottom of a silicon photonics (SiPh) chip is provided. The connector comprises: a curved mirror; and a tilted flat mirror; wherein at least one of the curved mirror and the tilted flat mirror is formed on a hardened stamped imprint material that was deposited on the SiPh chip at least in a cavity thereof.

A method comprising: stamping imprint material that was deposited on a silicon photonics (SiPh) chip and at least in a cavity thereof to form a curved mirror shape and a tilted flat mirror shape; coating at least a portion of each the curved mirror shape and the tilted flat mirror shape with a reflective material to form a first curved mirror and first tilted flat mirror; and mounting the SiPh chip in a flip-chip orientation to a substrate.

A reflective structure includes an input/output port and an optical splitter coupled to the input/output port. The optical splitter has a first branch and a second branch. The reflective structure also includes a first resonant cavity optically coupled to the first branch of the optical splitter. The first resonant cavity comprises a first set of reflectors and a first waveguide region disposed between the first set of reflectors. The reflective structure further includes a second resonant cavity optically coupled to the second branch of the optical splitter. The second resonant cavity comprises a second set of reflectors and a second waveguide region disposed between the second set of reflectors.

A method forms a vertical output coupler for a waveguide that propagates light along a horizontal propagation direction, through a waveguide material that overlies a buried oxide layer. The method includes etching the waveguide to remove a portion of the waveguide. The etching forms at least a first plane that is at an edge of the waveguide, is adjacent to the removed portion of the waveguide, and is tilted at a vertical angle between 20 degrees and 70 degrees with respect to the propagation direction. The method further includes coating the first tilted plane with a reflective metal to form a mirror, such that the mirror reflects the light into a direction having a vertical component.