A method for producing a semiconductor optical device includes the steps of bonding a semiconductor chip to an SOI substrate having a waveguide, the semiconductor chip having an optical gain and including a first cladding layer, a core layer, and a second cladding layer that contain III-V group compound semiconductors and are sequentially stacked in this order, forming a covered portion with a first insulating layer on the second cladding layer, etching partway in the thickness direction the second cladding layer exposed from the first insulating film, forming a second insulating film covering from the covered portion to a part of a remaining portion of the second cladding layer, and forming a first tapered portion that is disposed on the waveguide and tapered along the extending direction of the waveguide by etching the core layer and the second cladding layer exposed from the second insulating film.

An aluminosilicate glass having a composition according to the following formula (I):

(100−(1+a.sub.1+b.sub.1).Math.x)SiO.sub.2.Math.(x)Al.sub.2O.sub.3.Math.(a.sub.1.Math.x)MO.Math.(b.sub.1.Math.x)R (wt %)  (I)

in which MO is alkaline earth metal oxide, the alkaline earth metal M being one or more of Mg, Ca, Sr, and Ba, R comprises alkali metal oxide, the alkali metal being one or more of Li, Na, and K, x is at least 15, a.sub.1 is at least 0.35, b.sub.1 is at least 0.55, and wherein the product of a.sub.1 and b.sub.1 is at least 0.22.

The invention relates to an input or output facet for an on-chip optical waveguide, the facet comprising a grid of gradually expanding unit-cells such as cones or pyramids.

An optical device includes a transition unit in which a first waveguide and a second waveguide are disposed in an overlapped manner such that a magnitude relationship of an effective refractive index between the vertical modes propagating the first waveguide and the vertical modes propagating the second waveguide is inverted at the positions of input and output. The transition unit allows, at the input, the second waveguide to be a single mode waveguide and allows, at the output, the second waveguide to be a multi-mode waveguide through which TM0 light in the maximum vertical mode and light in a higher-order mode propagate. The optical device includes a removing unit that allows the second waveguide to be a single mode waveguide through which the TM0 light propagates by removing the light in the higher-order mode from the light received from the transition unit.

Structures for managing light polarization on a photonics chip and methods of forming a structure for managing light polarization on a photonics chip. A single-mode waveguiding structure is formed that includes a first waveguide core region and a second waveguide core region positioned above the first waveguide core region. The second waveguide core region includes a first section, a second section connected to the first section, and a third section connected to the second section. The second section has a first width at an intersection with the first section and a second width at an intersection with the third section. The second width is greater than the first width. The first and second waveguide core regions contain materials of different composition.

Disclosed are apparatuses for optical coupling and a system for communication. In one embodiment, an apparatus for optical coupling having an optical coupling region is disclosed. The apparatus for optical coupling includes a substrate and a core layer disposed on the substrate. The core layer includes a plurality of holes located in the optical coupling region. An effective refractive index of the core layer gradually decrease from a first end of the optical coupling region to a second end of the optical coupling region.

An optical phase shifter may include a waveguide core that has a top surface, and a semiconductor contact that is laterally displaced relative to the waveguide core and is electrically connected to the waveguide core. A top surface of the semiconductor contact is above the top surface of the waveguide core. The waveguide core may include a p-type core region and an n-type core region. A p-type semiconductor region may be in physical contact with the n-type core region of the waveguide core, and an n-type semiconductor region may be in physical contact with the p-type core region of the waveguide core. A phase shifter region and a light-emitting region may be disposed at different depth levels, and the light-emitting region may emit light from a phase shifter region that is in a position adjacent to the light-emitting region.

A strip-loaded optical waveguide includes a slab layer, a strip layer, and a cladding region. The slab layer has a first optical refractive index and a first width measured in a transverse direction that is perpendicular to a light propagation direction through the strip-loaded optical waveguide. The strip layer is disposed above the slab layer. The strip layer has a second optical refractive index and a second width as measured the transverse direction. The second width is less than the first width of the slab layer. The second optical refractive index is less than the first optical refractive index of the slab layer. The cladding region is disposed above the slab layer and above the strip layer. The cladding region has a third optical refractive index that is less than the second optical refractive index of the strip layer.

Disclosed are apparatuses for optical coupling and a system for communication. In one embodiment, an apparatus for optical coupling having an optical coupling region is disclosed. The apparatus for optical coupling includes a substrate and a core layer disposed on the substrate. The core layer includes a plurality of holes located in the optical coupling region. An effective refractive index of the core layer gradually decrease from a first end of the optical coupling region to a second end of the optical coupling region.

An optical phase shifter may include a waveguide core that has a top surface, and a semiconductor contact that is laterally displaced relative to the waveguide core and is electrically connected to the waveguide core. A top surface of the semiconductor contact is above the top surface of the waveguide core. The waveguide core may include a p-type core region and an n-type core region. A p-type semiconductor region may be in physical contact with the n-type core region of the waveguide core, and an n-type semiconductor region may be in physical contact with the p-type core region of the waveguide core. A phase shifter region and a light-emitting region may be disposed at different depth levels, and the light-emitting region may emit light from a phase shifter region that is in a position adjacent to the light-emitting region.