Imec Vzw

Universiteit Gent

Katholieke Universiteit Leuven, Ku Leuven R&d

Stichting Imec Nederland

Katholieke Universiteit Leuven

Ashwyn Srinivasan

Joris Van Campenhout

Maria Ioanna Pantouvaki

Bernardette Kunert

Clement Merckling

Peter Offermans

Peter Verheyen

Davide Guermandi

Philippe Absil

Irina Kulkova

A circuit for optoelectronic down-conversion of a terahertz, THz, signal comprises a first photodiode and a second photodiode configured to be excited by an optical beat signal. The photodiodes are coupled in series through a common antenna. The terminals of the antenna are coupled to form an output terminal and the antenna is configured to receive the terahertz, THz, signal. The photodiodes thereby, via the optical beat signal, respectively, down-convert the THz signal and generate a current comprising an intermediate frequency, IF, component and a direct current, DC, component. The respective generated currents are summed at the output terminal, thereby obtaining the IF components and cancelling the DC components.

Circuit for optoelectronic down-conversion of THz signals

An avalanche photodiode (APD) device, in particular, a lateral separate absorption charge multiplication (SACM) APD device, and a method for its fabrication is provided. The APD device comprises a first contact region and a second contact region formed in a semiconductor layer. Further, the APD device comprises an absorption region formed on the semiconductor layer, wherein the absorption region is at least partly formed on a first region of the semiconductor layer, wherein the first region is arranged between the first contact region and the second contact region. The APD device further includes a charge region formed in the semiconductor layer between the first region and the second contact region, and an amplification region formed in the semiconductor layer between the charge region and the second contact region. At least the absorption region is curved on the semiconductor layer.

Avalanche photodiode device with a curved absorption region

A method is provided for fabricating an avalanche photodiode (APD) device, in particular, a separate absorption charge multiplication (SACM) APD device. The method includes forming a first contact region and a second contact region in a semiconductor layer. Further, the method includes forming a first mask layer above at least a first contact region of the semiconductor layer adjacent to the first contact region, and forming a second mask layer above and laterally overlapping the first mask layer. Thereby, a mask window is defined by the first mask layer and the second mask layer, and the first mask layer and/or the second mask layer are formed above a second contact region of the semiconductor layer adjacent to the second contact region. Further, the method includes forming a charge region in the semiconductor layer through the mask window, wherein the charge region is formed between the first contact region and the second contact region, and comprises forming an absorption region on the first contact region using the first mask layer. An APD fabricated by the disclosed method is also provided.

Method for fabricating an avalanche photodiode device

An electrically-operated semiconductor laser device and method for forming the laser device are provided. The laser device includes a fin structure to which a waveguide is optically coupled. The waveguide is optically coupled to passive waveguides at either end thereof. The fin structure includes an array of fin elements, each fin element comprising Group III-V materials.

Laser devices

A III-V semiconductor waveguide nanoridge structure having a narrow supporting base with a freestanding wider body portion on top, is disclosed. In one aspect, the III-V waveguide includes a PIN diode. The waveguide comprises a III-V semiconductor waveguide core formed in the freestanding wider body portion; at least one heterojunction incorporated in the III-V semiconductor waveguide core; a bottom doped region of a first polarity positioned at a bottom of the narrow supporting base, forming a lower contact; and an upper doped region of a second polarity, forming an upper contact. The upper contact is positioned in at least one side wall of the freestanding wider body portion.

III-V semiconductor waveguide nanoridge structure

Example embodiments relate to an electro-optical device that includes a vertical p-i-n diode waveguide. The electro-optical device includes a waveguide portion adapted for propagating a multimode wave, the waveguide portion including an intrinsic semiconductor region of the vertical p-i-n diode, a first contact and a second contact for electrically contacting a first electrode and a second electrode of the vertical p-i-n diode. The device also includes an input section for coupling radiation into the waveguide portion and an output section for coupling radiation out of the waveguide portion. The input section, the output section, and the waveguide portion are configured to support a multimode interference pattern for the multimode wave with an optical field with a lateral inhomogeneous spatial distribution in the waveguide portion including regions with higher optical field intensity and regions with lower optical field intensity. The second contact physically contacts the second electrode.

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Heverlee, Belgium

Ashwyn Srinivasan