Abstract: A multiple-core optical waveguide comprises: a substrate; lower and upper waveguide core layers; a waveguide core between the upper and lower waveguide core layers; upper and lower cladding; and middle cladding between the upper and lower waveguide core layers substantially surrounding the waveguide core. Each of the lower, middle, and upper claddings has a refractive index less than refractive indices of the lower waveguide core layer, the upper waveguide core layer, and the waveguide core. Along at least a given portion of the optical waveguide, the upper and lower waveguide core layers extend bilaterally substantially beyond the lateral extent of a propagating optical mode supported by the optical waveguide, the lateral extent of the supported optical mode being determined at least in part by the width of the waveguide core along the given portion of the optical waveguide.

Abstract: An optical apparatus comprises an optical device formed on a device substrate, a first optical waveguide formed on the substrate or on the optical device, and a second, mechanically discrete optical waveguide assembled with the device substrate, optical device, or first optical waveguide. The first optical waveguide is arranged for transferring an optical signal between the optical device and the first optical waveguide. The first and second optical waveguides are arranged, when the second optical waveguide is assembled with the device substrate, optical device, or first optical waveguide, for transferring the optical signal therebetween via optical transverse coupling.

Abstract: A multiple-core planar optical waveguide comprises: a substantially planar waveguide substrate; a lower waveguide core; an upper waveguide core; lower cladding between the substrate and the lower waveguide core; middle cladding between the waveguide cores; and upper cladding above the upper waveguide core. Overlapping portions of the waveguide cores are positioned one above the other and substantially parallel. The lower, middle, and upper claddings have refractive indices less than refractive indices of the lower and upper waveguide cores. The widths of the waveguide cores are substantially larger their thicknesses along their overlapping portions. The overlapping portions of the waveguide cores jointly support a propagating optical mode.

Abstract: A substantially flat upper cladding surface over a waveguide core facilitates transverse-coupling between assembled waveguides, and/or provides mechanical alignment and/or support. An embedding medium may be employed for securing optical assemblies and protecting optical surfaces thereof. Structural elements fabricated with a low-profile core may be employed for providing mechanical alignment and/or support, aiding in the encapsulation process, and so forth.

Abstract: An optical apparatus comprises an optical device fabricated on a substrate, an external-transfer optical waveguide fabricated on the substrate and/or on the optical device, and a transmission optical waveguide. The optical device and/or the external-transfer waveguide are adapted for and positioned for transfer of optical power therebetween (end-transfer or transverse-transfer). The external-transfer waveguide and/or the transmission waveguide are adapted for transverse-transfer of optical power therebetween (mode-interference-coupled or adiabatic). The transmission waveguide is initially provided as a component mechanically separate from the substrate, device, and external-transfer waveguide. Assembly of the transmission waveguide with the substrate, device, and/or external-transfer waveguide results in relative positioning of the external-transfer waveguide and the transmission waveguide for enabling transverse-transfer of optical power therebetween.

Abstract: A multiple-core optical waveguide comprises: a substrate; lower and upper waveguide core layers; a waveguide core between the upper and lower waveguide core layers; upper and lower cladding; and middle cladding between the upper and lower waveguide core layers substantially surrounding the waveguide core. Each of the lower, middle, and upper claddings has a refractive index less than refractive indices of the lower waveguide core layer, the upper waveguide core layer, and the waveguide core. Along at least a given portion of the optical waveguide, the upper and lower waveguide core layers extend bilaterally substantially beyond the lateral extent of a propagating optical mode supported by the optical waveguide, the lateral extent of the supported optical mode being determined at least in part by the width of the waveguide core along the given portion of the optical waveguide.

Abstract: An optical component may comprise a horizontal member with two side walls and a substantially transparent end wall protruding from the horizontal member. The end wall, side walls and horizontal member may partially enclose an interior volume, and optical functionality is imparted in any suitable manner on at least a portion of the end wall. An optical assembly may comprise such an optical component mounted on a waveguide substrate along with a planar waveguide and a second waveguide, which are end-coupled by either reflection from the optical component end wall or transmission through the optical component end wall. An end portion of a planar waveguide may be received within the interior volume of the mounted component. Proper positioning of the optical component relative to the waveguides may be facilitated by alignment surfaces and/or alignment marks on the component and/or waveguide substrate.

Abstract: An optical apparatus comprises: a waveguide substrate; three planar optical waveguides formed on the substrate, each comprising a transmission core and cladding; a laser positioned to launch its optical output to propagate along the first waveguide; a photodetector positioned to receive an optical signal propagating along the second waveguide; and means formed on the substrate for i) transferring a first fraction of laser optical output propagating along the first waveguide to the second waveguide, and ii) transferring a second fraction of the laser optical output propagating along the first waveguide to the third waveguide. The transferring means may comprise: i) a pair of parallel spaced-apart tap core segments; ii) a branched splitter core; or iii) a lateral splitter core.

Abstract: An optical apparatus comprises a substrate, first and second transmission optical elements on the substrate, and an optical component (such as an isolator) and focusing optical element(s) on the substrate between the transmission elements. Transmission elements may include planar waveguide(s) formed on the substrate and/or optical fiber(s) mounted in groove(s) on the substrate. The focusing element(s) may include: gradient-index (GRIN) segment(s) mounted on the substrate or spliced onto a fiber, a focusing segment(s) of a planar waveguide, ball lens(es), aspheric lens(es), and/or Fresnel lens(es). A dual-lens optical assembly comprises a pair of GRIN segments secured to a substrate in one or more grooves, and may be formed from a common length of GRIN optical medium. An optical component (such as an isolator) is positioned between the paired GRIN segments, and optical power is transmitted by the dual-lens assembly between planar waveguide(s) and/or fiber(s) through the optical component.

Abstract: An optical apparatus comprises a semiconductor optical device waveguide formed on a semiconductor substrate, and an integrated end-coupled waveguide formed on the semiconductor substrate. The integrated waveguide may comprise materials differing from those of the device waveguide and the substrate. Spatially selective material processing may be employed for first forming the optical device waveguide on the substrate, and for subsequently depositing and forming the integrated end-coupled waveguide on the substrate. Spatially selective material processing enables accurate spatial mode matching and transverse alignment of the waveguides, and multiple device waveguides and corresponding integrated end-coupled waveguides may be fabricated concurrently on a common substrate on a wafer scale.

Abstract: The launch conditions (injected beam size/shape, radial/angular offset from the multimode fiber axis) may be varied to preferentially excite certain transverse modes of multimode optical fiber. To reduce multimode dispersion in the fiber, modes are excited having smaller amplitudes near fiber index defects. Launch conditions may be controlled using a substrate with grooves for launching and receiving fibers, a planar waveguide formed on a substrate along with a groove for aligning the multimode fiber and waveguide, or free-space optical components. A waveguide may provide the desired injected beam size/shape. Spatially selective material processing enables accurate alignment of the groove(s) (and hence the fiber(s) therein), yielding the desired radial/angular offsets.

Abstract: A grating-stabilized semiconductor laser comprises a semiconductor laser gain medium, an integrated low-index waveguide, and a waveguide grating segment providing optical feedback for laser oscillation. The laser may be adapted for multi-mode or single-mode operation. A multiple-mode laser may oscillate with reduced power and/or wavelength fluctuations associated with longitudinal mode wavelength shifts, relative to Fabry-Perot lasers lacking gratings. A single-mode laser may include a compensator, wavelength reference, and detector for generating an error signal, and a feedback mechanism for controlling the compensator for maintaining the laser wavelength locked to the reference. The laser may include means for altering, enhancing, tuning, and/or stabilizing the waveguide grating reflectivity spectral profile. The laser may be adapted for optical transverse-coupling to another waveguide.

Abstract: A multiple-core planar optical waveguide comprises: a substantially planar waveguide substrate; a lower waveguide core; an upper waveguide core; lower cladding between the substrate and the lower waveguide core; and upper cladding above the upper waveguide core. At least a portion the upper waveguide core is positioned above and substantially parallel to at least a portion of the lower waveguide core. The lower and upper claddings have refractive indices less than refractive indices of the lower and upper waveguide cores. The width of the lower waveguide core is substantially larger than its thickness along at least a portion of its length, and is substantially flat along that portion of its length, thereby yielding a substantially flat surface for forming at least a portion of the upper waveguide core.

Abstract: A multiple-core optical waveguide comprises: a substrate; lower and upper waveguide core layers; a waveguide core between the upper and lower waveguide core layers; upper and lower cladding; and middle cladding between the upper and lower waveguide core layers substantially surrounding the waveguide core. Each of the lower, middle, and upper claddings has a refractive index less than refractive indices of the lower waveguide core layer, the upper waveguide core layer, and the waveguide core. Along at least a given portion of the optical waveguide, the upper and lower waveguide core layers extend bilaterally substantially beyond the lateral extent of a propagating optical mode supported by the optical waveguide, the lateral extent of the supported optical mode being determined at least in part by the width of the waveguide core along the given portion of the optical waveguide.

Abstract: An optical apparatus comprises an optical device fabricated on a substrate, an external-transfer optical waveguide fabricated on the substrate and/or on the optical device, and a transmission optical waveguide. The optical device and/or the external-transfer waveguide are adapted for and positioned for transfer of optical power therebetween (end-transfer or transverse-transfer). The external-transfer waveguide and/or the transmission waveguide are adapted for transverse-transfer of optical power therebetween (mode-interference-coupled or adiabatic). The transmission waveguide is initially provided as a component mechanically separate from the substrate, device, and external-transfer waveguide. Assembly of the transmission waveguide with the substrate, device, and/or external-transfer waveguide results in relative positioning of the external-transfer waveguide and the transmission waveguide for enabling transverse-transfer of optical power therebetween.

Abstract: Discrete first and second optical transmission subunits are formed each having a corresponding transmission optical waveguide with a corresponding optical junction region. The first transmission optical waveguide is a planar optical waveguide formed on a substrate. The first transmission optical waveguide or the second transmission optical waveguide is adapted for enabling substantially adiabatic transverse-transfer of optical power between the optical waveguides at the respective optical junction regions. The first and second optical transmission subunits are assembled together to form an optical apparatus.

Abstract: A photodetector comprises a semiconductor substrate with entrance and reflecting faces formed at the substrate upper surface. The reflecting face forms an acute angle with the substrate surface and is positioned so that an optical beam transmitted through the entrance face into the substrate is internally reflected from the reflecting face toward the substrate upper surface. A photodetector active region is formed on the substrate upper surface and is positioned so that the reflected optical beam impinges on the active region. The photodetector may be mounted on a second substrate for receiving an optical beam from a planar waveguide formed on the second substrate or an optical fiber mounted in a groove on the second substrate.

Abstract: An optical component may comprise a horizontal member with two side walls and a substantially transparent end wall protruding from the horizontal member. The end wall, side walls and horizontal member may partially enclose an interior volume, and optical functionality is imparted in any suitable manner on at least a portion of the end wall. An optical assembly may comprise such an optical component mounted on a waveguide substrate along with a planar waveguide and a second waveguide, which are end-coupled by either reflection from the optical component end wall or transmission through the optical component end wall. An end portion of a planar waveguide may be received within the interior volume of the mounted component. Proper positioning of the optical component relative to the waveguides may be facilitated by alignment surfaces and/or alignment marks on the component and/or waveguide substrate.

Abstract: Formation of a substantially flat upper cladding surface over a waveguide core facilitates transverse-coupling between assembled waveguides, and/or provides mechanical alignment and/or support. An embedding medium may be employed for securing optical assemblies and protecting optical surfaces thereof. Structural elements fabricated with a low-profile core may be employed for providing mechanical alignment and/or support, aiding in the encapsulation process, and so forth.

Abstract: A multi-layer laterally-confined dispersion-engineered optical waveguide may include one multi-layer reflector stack for guiding an optical mode along a surface thereof, or may include two multi-layer reflector stacks with a core therebetween for guiding an optical mode along the core. Dispersive properties of such multi-layer waveguides enable modal-index-matching between low-index optical fibers and/or waveguides and high-index integrated optical components and efficient transfer of optical signal power therebetween. Integrated optical devices incorporating such multi-layer waveguides may therefore exhibit low (<3 dB) insertion losses. Incorporation of an active layer (electro-optic, electro-absorptive, non-linear-optical) into such waveguides enables active control of optical loss and/or modal index with relatively low-voltage/low-intensity control signals. Integrated optical devices incorporating such waveguides may therefore exhibit relatively low drive signal requirements.