An optical mode-size converter is presented, which includes a guiding portion, wherein at least a portion of the guiding portion extends between a first end and a second end along a first path, a first strip with a first refractive index, and a second strip with a second refractive index. The first strip and the second strip are embedded within the guiding portion extending along the first path such that a first optical mode received at the first end reaches the first strip before the second strip and such that the second strip extends to the second end. The first refractive index and the second refractive index are higher than a refractive index of the guiding portion, and a section of the first strip and a section of the second strip overlap to form an evanescent coupling region, such that converter is responsive to a first optical mode received at the first end to convert the first optical mode into a second optical mode with a smaller mode size along the first path towards the second end.

The optical waveguide component of the present disclosure provides a configuration for optically connecting two optical waveguides composed of different materials with low loss. The first optical circuit including the core of a first material and a second optical circuit including a core of a second material are configured on a single substrate. The optical waveguide component of the present disclosure includes an optical connection part between two optical circuits, and has a double structure in which a core cross-sectional region of one optical waveguide is included in a core cross-sectional region of the other optical waveguide between the two optical waveguides. The optical connection part is provided with a protrusion part of the underclad extending along the first core from the high-level surface toward the low-level surface of the underclad toward, and the width of the protrusion part is gradually narrowed toward the second optical circuit.

The present application discloses a polarization beam splitter (PBS). The PBS includes a silicon substrate and a planar structure formed thereon characterized by an isosceles trapezoid shape with a first parallel side and a second parallel side connected by two tapered sides. The first parallel side has longer width than the second parallel side, both of which is separated by a length no greater than 100 μm along a line of symmetry bisecting the pair of parallel sides. The PBS further includes a pair of input ports coupled to the first parallel side and a pair of output ports coupled to the second parallel side. The planar structure is configured to receive an input light wave of any wavelength in C-band via one input port and split to a TE-mode light wave and a TM-mode light wave respectively outputting to the pair of output ports.

Structures for an optical power splitter and methods of forming a structure for an optical power splitter. A first waveguide core includes a portion positioned over a multimode interference region, a second waveguide core includes a portion positioned over the multimode interference region, and a third waveguide core includes a portion positioned over the multimode interference region. The first waveguide core provides an input port to the optical power splitter. The second waveguide core provides a first output port from the optical power splitter, and the third waveguide core provides a second output port from the optical power splitter.

System and methods for optical power distribution to a large numbers of sample wells within an integrated device that can analyze single molecules and perform nucleic acid sequencing are described. The integrated device may include a grating coupler configured to receive an optical beam from an optical source and optical splitters configured to divide optical power of the grating coupler to waveguides of the integrated device positioned to couple with the sample wells. Outputs of the grating coupler may vary in one or more dimensions to account for an optical intensity profile of the optical source.

The present disclosure relates to semiconductor structures and, more particularly, to multi-mode optical waveguide structures with isolated absorbers and methods of manufacture. The structure includes: a waveguide structure including tapered segments; and at least one isolated waveguide absorber adjacent to the waveguide structure along its length.

An embodiment photodetector includes a clad layer formed on a substrate, a first semiconductor layer formed on the clad layer, and a second semiconductor layer and a third semiconductor layer with the first semiconductor layer interposed therebetween formed on the clad layer. The photodetector includes a light absorbing layer made of an n-type III-V compound semiconductor formed on the first semiconductor layer through an insulating layer.

Integrated passive/active modulator units, integrated passive/active modulators comprising one or more units, and corresponding methods of fabrication and use are provided. In an example embodiment, a unit comprises an upstream passive portion comprising a passive waveguide; a downstream passive portion comprising a continuation of the passive waveguide; and an active portion between the upstream passive portion and the downstream passive portion. The active portion comprises an active waveguide and electrical contacts in electrical communication with the active waveguide. The active waveguide comprises an upstream taper and/or a downstream taper. The upstream taper is configured to optically couple the active waveguide to the passive waveguide of the upstream portion and the downstream taper is configured to optically couple the active waveguide to the continuation of the passive waveguide of the downstream portion.

A spot size converter includes a first waveguide including a first core layer, the first waveguide propagating light; and a second waveguide including a second core layer and provided on the first waveguide, the second waveguide propagating light. The first waveguide and the second waveguide extend in a waveguide direction. A first region and a second region are provided continuously along the waveguide direction. In the first region, the second waveguide has a tapered shape in a cross section which becomes narrower as going up away from the first waveguide. An angle between a side surface of the second waveguide and a bottom surface of the second waveguide is 60° or less.

A composite all optical-fibre based tapered photonic waveguide (110) including a single or multiple secondary waveguides (120) within or around a primary waveguide (118) is described. The composite optical fibre may also be termed a beam tailoring optical fibre (BT Fibre) (110). In use, at thelarger secondary end (114) both the primary waveguide (118) and the secondary waveguide/s (120) may guide modes at a particular wavelength. However, at the same wavelength, adiabatically tapering down the waveguides (118, 120) reduces the dimensions of the secondary waveguide/s (120) such that all the secondary waveguide/s (120) become effectively non-guiding at the smaller primary end (112), whilst the primary waveguide (118) still guides. In other words, the composite optical fibre is a spatially modulating optical fibre (110).