Nexus Photonics LLC

Minh Tran

Tin Komljenovic

Chong Zhang

Hyun Dai Park

Zeyu Zhang

Hyundai Park

A device includes a first element having a passive waveguide structure supporting a first optical mode, a second element providing heat spreading functionality, a third element thermally coupled to the second element, having an active waveguide structure supporting a second optical mode, and a fourth element, at least partly butt-coupled to the third element, having an intermediate waveguide structure supporting intermediate optical modes. A tapered waveguide structure in either one of the first and fourth elements facilitates efficient adiabatic transformation between the first optical mode and one of the intermediate optical modes. No adiabatic transformation occurs between any of the intermediate optical modes and the second optical mode. Mutual alignments of the first, second, third and fourth elements are defined using lithographic alignment marks that facilitate precise alignment between layers formed during processing steps of fabricating the first, second, third and fourth elements.

Heterogeneously integrated photonic platform with improved thermal performance

A device has first, second and third elements fabricated on a common substrate. The first element supports a first optical mode in an active waveguide structure characterized by a mesa. The second element supports a second optical mode in a passive waveguide structure. The third element, at least partly butt-coupled to the first element, supports an intermediate optical mode in an intermediate waveguide structure characterized by a waveguide core cross section including a shallow step. A tapered waveguide structure in at least one of the second and third elements facilitates efficient adiabatic transformation between the second optical mode and the intermediate optical mode. No adiabatic transformation occurs between the intermediate optical mode and the first optical mode. Lithographic alignment marks facilitate precise alignment of the three elements during device fabrication.

Mode control in heterogeneously integrated photonics

A device has first, second and third elements fabricated on a common substrate. The first element supports a first optical mode in a first active waveguide, the second element supports a second optical mode in a second passive waveguide, and the third element, at least partly butt-coupled to the first element, has a bottom waveguide, supporting a bottom intermediate mode, overlying a top waveguide, supporting a top intermediate mode. A tapered waveguide structure in the top waveguide facilitates efficient adiabatic transformation between the top intermediate mode and the bottom intermediate mode. Tapering in at least one of the bottom waveguide and the second waveguide facilitates efficient adiabatic transformation between the second optical mode and the bottom intermediate optical mode. No adiabatic transformation occurs between either of the intermediate optical modes and the first optical mode. Lithographic alignment marks facilitate precise alignment of the three elements during device fabrication.

Heterogenously integrated short wavelength photonic platform with optimally minimal reflections

A device comprises first, second, third and fourth elements fabricated on a common substrate. The first element comprises an active waveguide structure supporting a first optical mode, the second element comprises a passive waveguide structure supporting a second optical mode, the third element, at least partly butt-coupled to the first element, comprises an intermediate waveguide structure supporting intermediate optical modes, and a fourth element comprising TCO material that is attached to the first element. If the first optical mode differs from the second optical mode by more than a predetermined amount, a tapered waveguide structure in at least one of the second and third elements facilitates efficient adiabatic transformation. No adiabatic transformation occurs between any of the intermediate optical modes and the first optical mode. Mutual alignments of the first, the second, the third, and the fourth elements are defined using lithographic alignment marks.

Heterogeneous GaN lasers and active components

A radio frequency generator has first and second lasers configured to emit first and second optical outputs; a reference module configured to receive at least part of the first and second optical outputs from the first and second lasers; a control module connected to the first and second lasers and to the reference module; and an optical-to-electrical (O/E) converter configured to process optical signals, originating from the first and second single-frequency lasers, to provide a radio frequency output. Another radio frequency generator has a control module; and a reference module connected to the control module. The reference module includes a photonic integrated circuit (PIC) having first and second single-frequency lasers configured to emit first and second optical outputs; an unbalanced Mach-Zehnder interferometer (UMZI) with first and second 3×3 optical splitter/combiners; first and second peripheral splitter/combiners; and an output splitter/combiner.

Stabilized frequency generator

A device comprises three elements, realized as photonic integrated circuits. The first element comprises a tunable semiconductor laser emitting light at a laser output wavelength. The second element comprises a wavelength selective element, coupled to the first element. The third element comprises N photodetectors where N>=2, coupled to the second element. Light coupled into the second element from the first element is de-multiplexed by the wavelength selective element such that a ratio of light power coupled from the second element into one of the N photodetectors to light power coupled from the second element into another one of the N photodetectors is a function of the laser output wavelength. The responses of the N photodetectors facilitate at least one of measurement and control of the laser output wavelength.

Wavelength-controlled tunable chip-scale laser

A device comprises first, second and third elements fabricated on a common substrate. The first element comprises an active waveguide structure comprising: a first portion supporting a first optical mode. The second element comprises a passive waveguide structure supporting a second optical mode. The third element, at least partly butt-coupled to the second portion, comprises an intermediate waveguide structure supporting intermediate optical modes. At least part of the second element is non-linear, supporting frequency conversion. A tapered waveguide structure in at least one of the second and third elements facilitates efficient adiabatic transformation between the first optical mode and one intermediate optical mode. No adiabatic transformation occurs between any intermediate optical mode and the first optical mode. Mutual alignments of the elements are defined using lithographic alignment marks.

Heterogeneously integrated photonic platform with non-linear frequency conversion element

A device comprises three elements. The first element, comprising an optical gain structure and a laser cavity mirror structure, couples light to the second element, comprising a phase tuner. The second element couples phase tuned light to the third element. The third element, comprising an optical resonator with first and second coupler/splitter structures, provides a primary optical output from the second coupler/splitter structure. Light coupled into the optical resonator through the first coupler/splitter structure and then coupled out of the optical resonator though the first coupler/splitter structure is injected back into the optical gain structure through the second element. Light coupled out of the optical resonator through the second coupler/splitter structure is provided as the primary optical output. Characteristic of the coupler/splitter structures and the optical resonator are selected such that the light injected back into the optical gain structure reduces linewidth, and noise in primary optical output is suppressed.

Low noise lasers with resonator filters

A device comprises first, second and third elements fabricated on a common substrate. The first element comprises an active waveguide structure comprising electrically pumped optical source supporting a first optical mode. The second element comprises a passive waveguide structure supporting a second optical mode in at least part of the second element. The third element, at least partly butt-coupled to the first element, comprises an intermediate waveguide structure supporting intermediate optical modes. At least part of the second element supports at least one optical mode that interacts with rare-earth dopants. A tapered waveguide structure in at least one of the second and the third elements facilitates efficient adiabatic transformation between the second optical mode and at least one of the intermediate optical modes. No adiabatic transformation occurs between any of the intermediate optical modes and the first optical mode. Mutual alignments of the elements are defined using lithographic alignment marks.

Heterogeneous photonic integrated circuits with doped waveguides

A device includes three elements fabricated on a common substrate. The first element includes an active waveguide structure having at least three sub-layers supporting a first optical mode. The second element has a passive waveguide structure supporting a second optical mode, and the third element, butt-coupled to the first element, has an intermediate waveguide structure supporting intermediate optical modes. One sub-layer in the active waveguide structure includes an n-contact layer, another sub-layer includes a p-contact layer, and a third sub-layer includes an active region. A tapered waveguide structure in at least one of the second and third elements facilitates efficient adiabatic transformation between the second optical mode and an intermediate optical mode. No adiabatic transformation occurs between that intermediate optical mode and the first optical mode. Mutual alignments of the three elements are defined using lithographic alignment marks that facilitate precise alignment between layers formed fabrication of the elements.

Integrated GaAs active devices with improved optical coupling to dielectric waveguides

A device providing efficient transformation between an initial optical mode and a second optical mode includes first, second and third elements fabricated on a common substrate. The first element includes first and second active sub-layers supporting initial and final optical modes with efficient mode transformation therebetween. The second element includes a passive waveguide structure supporting a second optical mode. The third element, at least partly butt-coupled to the first element, includes an intermediate waveguide structure supporting an intermediate optical mode. If the final optical mode differs from the second optical mode by more than a predetermined amount, a tapered waveguide structure in the second or third elements facilitates efficient transformation between the intermediate optical mode and the second optical mode. Precise alignment of sub-elements formed in one of the elements, relative to sub-elements formed in another one of the elements, is defined using lithographic alignment marks.

Active-passive photonic integrated circuit platform

An optical device comprises first, second and third elements fabricated on a common substrate. The first element comprises an active waveguide structure supporting a first optical mode, the second element, fabricated on a planarized top surface of the first element, comprises a passive waveguide structure supporting a second optical mode, and the third element, at least partly butt-coupled to the first element, comprises an intermediate waveguide structure, positioned such that a top surface of the intermediate structure underlies a bottom surface of the passive waveguide structure. If the first optical mode differs from the second optical mode by more than a predetermined amount, a tapered waveguide structure in at least one of the second and third elements facilitates efficient adiabatic transformation between the first optical mode and the second optical mode. Mutual alignments of the first, second and third elements are defined using lithographic alignment marks.

Heterogeneously integrated photonic devices with improved optical coupling between waveguides

A device comprises first, second and third elements fabricated on a common substrate. The first element comprises an active waveguide structure comprising: one portion, of effective cross-sectional area A, supporting a first optical mode; and a second portion, butt-coupled to the first portion, of effective cross-sectional area A&#x3e;A. The second element comprises a passive waveguide structure supporting a second optical mode. The third element, at least partly butt-coupled to the second portion, comprises an intermediate waveguide structure supporting intermediate optical modes. If the first optical mode differs from the second optical mode by more than a predetermined amount, a tapered waveguide structure in at least one of the second and third elements facilitates efficient adiabatic transformation between the first optical mode and one intermediate optical mode. No adiabatic transformation occurs between any intermediate optical mode and the first optical mode. Mutual alignments of the elements are defined using lithographic marks.

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Goleta, CA, United States of America

Minh Tran