Optical alignment of optical subassembly and optoelectronic device is achieved using an external source and an external receiver, passing optical signal through a passive waveguide in the optoelectronic device, via alignment reflective surface features provided on the optical subassembly. The optical subassembly is provided with a first alignment reflective surface directing alignment signal from the source to a grating coupler at the input of the waveguide, and a second alignment reflective surface directing to the receiver the alignment signal directed from a grating coupler at the output of the waveguide after the alignment signal has been transmitted from the input to the output through the waveguide. By adjusting the relative position between the optical subassembly and the optoelectronic device, and detecting the maximum optical power of the alignment signal reflected from the second alignment reflective surface, the position of best optical alignment of the optical subassembly and the optoelectronic device can be determined.

Optical alignment of optical subassembly and optoelectronic device is achieved using an external source and an external receiver, passing optical signal through a passive waveguide in the optoelectronic device, via alignment reflective surface features provided on the optical subassembly. The optical subassembly is provided with a first alignment reflective surface directing alignment signal from the source to a grating coupler at the input of the waveguide, and a second alignment reflective surface directing to the receiver the alignment signal directed from a grating coupler at the output of the waveguide after the alignment signal has been transmitted from the input to the output through the waveguide. By adjusting the relative position between the optical subassembly and the optoelectronic device, and detecting the maximum optical power of the alignment signal reflected from the second alignment reflective surface, the position of best optical alignment of the optical subassembly and the optoelectronic device can be determined.

Embodiments of the present disclosure are directed toward techniques and configurations for an optical device having a multiplexer and/or demultiplexer with an input and/or output optical waveguide including one or more waveguide segments tapered according to a non-linear function such as a curve. In embodiments, the one or more waveguide segments is tapered according to, e.g., a quadratic function, a parabolic function, or an exponential function. In accordance with some embodiments, the tapered segment assists in spatially dispersing the propagating light along a substantially uniform phase wavefront at a mirror that includes an echelle grating surface that is shaped to receive/reflect the light at the substantially uniform phase wavefront. In embodiments, the one or more waveguide segments is tapered according to a curve to receive a portion of light from the substantially uniform phase wavefront at the echelle grating surface. Additional embodiments may be described and claimed.

Embodiments of the present disclosure are directed toward techniques and configurations for an optical device having a multiplexer and/or demultiplexer with an input and/or output optical waveguide including one or more waveguide segments tapered according to a non-linear function such as a curve. In embodiments, the one or more waveguide segments is tapered according to, e.g., a quadratic function, a parabolic function, or an exponential function. In accordance with some embodiments, the tapered segment assists in spatially dispersing the propagating light along a substantially uniform phase wavefront at a mirror that includes an echelle grating surface that is shaped to receive/reflect the light at the substantially uniform phase wavefront. In embodiments, the one or more waveguide segments is tapered according to a curve to receive a portion of light from the substantially uniform phase wavefront at the echelle grating surface. Additional embodiments may be described and claimed.

A light flux diameter expanding element includes a light guiding plate with a light input face and a light output face, and with a thickness of 0.2 mm to 0.8 mm; a diffraction grating on the input side; and a diffraction grating on the output side, and is provided so as to have the same grating period as that of the diffraction grating on the input side, in which a forming region of the diffraction grating on the input side is smaller than that of the output side, and a grating period of the diffraction grating on the input side is a period in which a small diffraction angle in diffraction angles of +1-st order diffracted light and 1-st order diffracted light, which are diffracted in the diffraction grating on the input side, in the light guiding plate becomes larger than a critical angle of the light guiding plate.

A light flux diameter expanding element includes a light guiding plate with a light input face and a light output face, and with a thickness of 0.2 mm to 0.8 mm; a diffraction grating on the input side; and a diffraction grating on the output side, and is provided so as to have the same grating period as that of the diffraction grating on the input side, in which a forming region of the diffraction grating on the input side is smaller than that of the output side, and a grating period of the diffraction grating on the input side is a period in which a small diffraction angle in diffraction angles of +1-st order diffracted light and 1-st order diffracted light, which are diffracted in the diffraction grating on the input side, in the light guiding plate becomes larger than a critical angle of the light guiding plate.

Provided are a Bragg grating and a spectroscopy device including the same. The Bragg grating is disposed at each of opposite ends of a resonator for reflecting light of a certain wavelength band and includes a core member extending from a waveguide of the resonator in a lengthwise direction of the waveguide; a plurality of first refractive members protruding from the core member and spaced apart from each other along the lengthwise direction; and a second refractive member filling spaces between the first refractive members and having a refractive index different from a refractive index of the first refractive members.

Provided are a Bragg grating and a spectroscopy device including the same. The Bragg grating is disposed at each of opposite ends of a resonator for reflecting light of a certain wavelength band and includes a core member extending from a waveguide of the resonator in a lengthwise direction of the waveguide; a plurality of first refractive members protruding from the core member and spaced apart from each other along the lengthwise direction; and a second refractive member filling spaces between the first refractive members and having a refractive index different from a refractive index of the first refractive members.

An example device in accordance with an aspect of the present disclosure includes a slab to transmit light, and a plurality of lenses and filters disposed on first and second surfaces of the slab. The lenses include an anti-reflective coating on at least one of the plurality of lenses at an end of the slab to couple light through the anti-reflective coating, and a reflective coating disposed on remaining ones of the plurality of lenses to cause the lenses to reflect light. The filters are offset from the lenses to form an optical zig-zag.

A semiconductor structure is disclosed. The semiconductor structure includes: a substrate and a gate element over the substrate. The gate element includes: a gate dielectric layer over the substrate; a gate electrode over the gate dielectric layer; and a waveguide passing through the gate electrode from a top surface of the gate electrode to a bottom surface of the gate electrode. A manufacturing method of the same is also disclosed.