Purdue Research Foundation

Minghao Qi

Min Teng

Kyunghun Han

Jian Wang

Yun Jo Lee

Li Fan

Sangsik Kim

Leo Tom Varghese

Ben Niu

Andrew Marc Weiner

Yi Xuan

Xiaoxiao Xue

Justin Christopher Wirth

A tunable optical comb generator having a source laser configured to generate a continuous wave (CW) light at a first wavelength; and a microresonator coupled to the source laser and configured to receive the CW light and generate an optical signal having a plurality of output wavelengths corresponding to the first wavelength. The generator includes a microresonator tuning device coupled to the microresonator and configured to tune the microresonator to compensate the microresonator for wavelength shifts. A control circuit is coupled to the microresonator tuning device and configured to generate a control signal to control the microresonator tuning device based on the optical signal. Multiple microresonators in the form of microrings may be included to tune the generator. A heater coupled to the microresonators may be used to adjust the microresonators.

Mode-locked and wavelength tunable optical frequency comb generation through dynamic control of microresonators

A semiconductor photonic device includes a substrate, facet(s), and optical coupler(s) associated with the facet(s). Each optical coupler can couple an electromagnetic field incident on the respective facet towards a buried waveguide as the electromagnetic field proceeds into the semiconductor photonic device. In some examples, each coupler has waveguides extending in a longitudinal direction and at least partly encapsulated within a cladding layer. In some examples, at least one waveguide tapers along its length. In some examples, at least one waveguide includes spaced-apart segments arranged to form a subwavelength grating (SWG) configured to entrain electromagnetic radiation.

Optical coupler having segmented waveguides for coupling electromagnetic field

A semiconductor photonic device includes a substrate, facet(s), and optical coupler(s) associated with the facet(s). Each optical coupler can couple an electromagnetic field incident on the respective facet towards the substrate as the electromagnetic field proceeds into the semiconductor photonic device. In some examples, each coupler has waveguides extending in a longitudinal direction and at least partly encapsulated within corresponding cladding layers. A first waveguide extends farther from the facet in the longitudinal direction than does a second waveguide. The second waveguide is located farther above the silicon substrate than is the first waveguide. The coupler can include a stack of waveguide assemblies. A lower waveguide assembly can include one waveguide. An intermediate or upper waveguide assembly can include multiple waveguides. In some examples, at least one waveguide tapers along its length.

Optical coupler

Optical coupler having exposed subwavelength gratings for coupling electromagnetic field

A method of fabricating an optical device includes forming on a semiconductor substrate a first optical cavity, a second optical cavity, a first light guide and a second light guide. The first light guide has an input, and is optically coupled to the first optical cavity by a first coupling strength. In addition, the first light guide is optically coupled to the second optical cavity by a second coupling strength. The second light guide has an output, and is coupled to the second optical cavity by a third coupling strength. The first coupling strength is greater than the second coupling strength, and the third coupling strength is greater than the second coupling strength.

Passive optical diode on semiconductor substrate

An optical device includes a first optical cavity, a second optical cavity, a first light guide and a second light guide. Each of the first and second optical cavities is formed on a semiconductor substrate, and is configured to store light. The first light guide has an input, and is optically coupled to the first optical cavity by a first coupling strength. In addition, the first light guide is optically coupled to the second optical cavity by a second coupling strength. The second light guide has an output, and is coupled to the second optical cavity by a third coupling strength. The first coupling strength is greater than the second coupling strength, and the third coupling strength is greater than the second coupling strength.

An optical device includes first and second waveguides and a micro-ring. The first waveguide is optically coupled to the micro-ring and is separated from the micro-ring by a first gap having a first gap distance. The second waveguide has a supply port, an output port, and a coupling portion optically coupled to the micro-ring. The coupling portion is separated from the micro-ring by a second gap having a second distance. The second gap distance is larger than the first gap distance. The second waveguide and the micro-ring cooperate to form a filter having a stop band. The first gap distance is selected such that a first optical signal on the first waveguide having a first strength causes a first shift in the stop band such that a first wavelength is within the stop band, and wherein the second gap distance is selected such that a second optical signal on the second waveguide having the first strength causes a second or no shift in the stop band such that the first wavelength is outside of the stop band.

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West Lafayette, IN, United States of America

Minghao Qi