Abstract: A waveguide platform and method of fabricating a waveguide platform on a silicon wafer; the method comprising: providing a wafer having a layer of crystalline silicon; lithographically defining a first region of the top layer; electrochemically etching the wave-guide platform to create porous silicon at the lithographically defined first region; epitaxially growing crystalline silicon on top of the porous silicon to create a first upper crystalline layer with a first buried porous silicon region underneath; wherein the first buried porous silicon region defines a taper between a first waveguide region of crystalline silicon having a first depth and a second waveguide region of crystalline silicon having a second depth which is smaller than the first depth.

Abstract: A source wafer for use in a micro-transfer printing process. The source wafer comprises: a substrate; a device coupon (110), including an optoelectronic device; and a breakable tether securing the device coupon to the substrate. The breakable tether includes one or more breaking regions which connect the breakable tether to the substrate.

Abstract: A semiconductor photodiode. The semiconductor photodiode including: an input waveguide, arranged to receive an optical signal at a first port and provide the optical signal from the second port; a photodiode waveguide, arranged to receive the optical signal from the second port of the input waveguide, and at least partially convert the optical signal into an electrical signal; and an electro-static defence component, located adjacent to the photodiode waveguide. The electro-static defence component and the photodiode waveguide are electrically connected in parallel.

Abstract: An optical modulator. The optical modulator comprising: a micro-ring resonator; and a bus waveguide, including an input waveguide region, an output waveguide region, and a coupling waveguide region optically coupled to the micro-ring resonator and located between the input waveguide region and the output waveguide region. The micro-ring resonator includes a modulation region, the modulation region being formed of a silicon portion and a III-V semiconductor portion separated by a crystalline rare earth oxide dielectric layer.

Abstract: A germanium based avalanche photo-diode device and method of manufacture thereof. The device including: a silicon substrate; a lower doped silicon region, positioned above the substrate; a silicon multiplication region, positioned above the lower doped silicon region; an intermediate doped silicon region, positioned above the silicon multiplication region; an un-doped germanium absorption region, position above the intermediate doped silicon region; an upper doped germanium region, positioned above the un-doped germanium absorption region; and an input silicon waveguide; wherein: the un-doped germanium absorption region and the upper doped germanium region form a germanium waveguide which is coupled to the input waveguide, and the device also includes a first electrode and a second electrode, and the first electrode extends laterally to contact the lower doped silicon region and the second electrode extends laterally to contact the upper doped germanium region.

Abstract: A method of preparing a device coupon for a micro-transfer printing process from a multi-layered stack located on a device wafer substrate. The multi-layered stack comprises a plurality of semiconductor layers. The method comprises steps of: (a) etching the multi-layered stack to form a multi-layered device coupon, including an optical component; and (b) etching a semiconductor layer of the multi-layered device coupon to form one or more tethers, said tethers securing the multi-layered device coupon to one or more supports.

Abstract: A method of transfer printing. The method comprising: providing a precursor photonic device, comprising a substrate and a bonding region, wherein the precursor photonic device includes one or more alignment marks located in or adjacent to the bonding region; providing a transfer die, said transfer die including one or more alignment marks; aligning the one or more alignment marks of the precursor photonic device with the one or more alignment marks of the transfer die; and bonding at least a part of the transfer die to the bonding region.

Abstract: An optoelectronic device comprising an optical waveguide formed in a silicon device layer of a silicon-on-insulator wafer. The optical waveguide including a semiconductor junction comprising a first doped region of semiconductor material and a second doped region of semiconductor material. The second doped region containing dopants of a different species to the first doped region. A first portion of the first doped region extends horizontally on top of the second doped region, a second portion of the first doped region extends vertically along a lateral side of the second doped region and a third portion of the first doped region protrudes as a salient from the first or second portion of the first doped region into the second doped region.

Abstract: A method of transfer printing. The method comprising: providing a precursor photonic device, comprising a substrate and a bonding region, wherein the precursor photonic device includes one or more alignment marks located in or adjacent to the bonding region; providing a transfer die, said transfer die including one or more alignment marks; aligning the one or more alignment marks of the precursor photonic device with the one or more alignment marks of the transfer die; and bonding at least a part of the transfer die to the bonding region.

Abstract: A phase shift keying modulator. The modulator comprises: a plurality of silicon waveguides provided in a device layer of a silicon-on-insulator platform, the silicon-on-insulator platform including one or more cavities; one or more III-V semiconductor based devices located within the one or more cavities of the silicon-on-insulator platform, each III-V semiconductor-based device including a III-V semiconductor based waveguide which is coupled at an input end to one of the plurality of silicon waveguides and coupled at an output end to another of the plurality of silicon waveguides, each III-V semiconductor based waveguide comprising an active phase modulating portion; and one or more contacts in electrical contact with each active phase modulating portion, such that the phase shift keying modulator is operable to modulate the phase of an optical wave passing through each active phase modulating portion.

Abstract: A phase shift keying modulator. The modulator comprises: a plurality of silicon waveguides provided in a device layer of a silicon-on-insulator platform, the silicon-on-insulator platform including one or more cavities; one or more III-V semiconductor based devices located within the one or more cavities of the silicon-on-insulator platform, each III-V semiconductor-based device including a III-V semiconductor based waveguide which is coupled at an input end to one of the plurality of silicon waveguides and coupled at an output end to another of the plurality of silicon waveguides, each III-V semiconductor based waveguide comprising an active phase modulating portion; and one or more contacts in electrical contact with each active phase modulating portion, such that the phase shift keying modulator is operable to modulate the phase of an optical wave passing through each active phase modulating portion.

Abstract: A method of manufacturing an optoelectronic device. The manufactured device includes a photonic component coupled to a waveguide. The method comprising: providing a device coupon, the device coupon including the photonic component; providing a silicon platform, the silicon platform comprising a cavity within which is a bonding surface for the device coupon; transfer printing the device coupon onto the cavity, such that a surface of the device coupon directly abuts the bonding surface and at least one channel is present between the device coupon and a sidewall of the cavity; and filling the at least one channel with a filling material via a spin-coating process, to form a bridge coupling the III-V semiconductor based photonic component to the silicon waveguide.

Abstract: An electro-optically active device comprising: a silicon on insulator (SOI) substrate including a silicon base layer, a buried oxide (BOX) layer on top of the silicon base layer, a silicon on insulator (SOI) layer on top of the BOX layer, and a substrate cavity which extends through the SOI layer, the BOX layer and into the silicon base layer, such that a base of the substrate cavity is formed by a portion of the silicon base layer; an electro-optically active waveguide including an electro-optically active stack within the substrate cavity; and a buffer region within the substrate cavity beneath the electro-optically active waveguide, the buffer region comprising a layer of Ge and a layer of GaAs.

Abstract: A method of transfer printing. The method comprising: providing a precursor photonic device, comprising a substrate and a bonding region, wherein the precursor photonic device includes one or more alignment marks located in or adjacent to the bonding region; providing a transfer die, said transfer die including one or more alignment marks; aligning the one or more alignment marks of the precursor photonic device with the one or more alignment marks of the transfer die; and bonding at least a part of the transfer die to the bonding region.

Abstract: An optoelectronic device, and a method of fabricating an optoelectronic device. The device comprising: a rib waveguide formed of doped silicon, said doped waveguide having a ridge portion, containing an uppermost surface and two sidewall surfaces; and a slab portion, adjacent to the two sidewall surfaces. The device further comprises: a metal contact layer, which directly abuts the uppermost surface and two sidewall surfaces, and which extends along a part of the slab portion so as to provide a Schottky barrier between the metal contact layer and the rib waveguide.

Abstract: A method of manufacturing an optoelectronic device. The manufactured device includes a photonic component coupled to a waveguide. The method comprising: providing a device coupon, the device coupon including the photonic component; providing a silicon platform, the silicon platform comprising a cavity within which is a bonding surface for the device coupon; transfer printing the device coupon onto the cavity, such that a surface of the device coupon directly abuts the bonding surface and at least one channel is present between the device coupon and a sidewall of the cavity; and filling the at least one channel with a filling material via a spin-coating process, to form a bridge coupling the III-V semiconductor based photonic component to the silicon waveguide.

Abstract: An electro-optically active device comprising: a silicon on insulator (SOI) substrate including a silicon base layer, a buried oxide (BOX) layer on top of the silicon base layer, a silicon on insulator (SOI) layer on top of the BOX layer, and a substrate cavity which extends through the SOI layer, the BOX layer and into the silicon base layer, such that a base of the substrate cavity is formed by a portion of the silicon base layer; an electro-optically active waveguide including an electro-optically active stack within the substrate cavity; and a buffer region within the substrate cavity beneath the electro-optically active waveguide, the buffer region comprising a layer of Ge and a layer of GaAs.

Abstract: A germanium based avalanche photo-diode device and method of manufacture thereof.

Abstract: An optoelectronic device. The device comprising: a multi-layered optically active stack, including one or more layers comprising a lll-V semiconductor material; an input waveguide, arranged to guide light into the stack; and an output waveguide, arranged to guide light out of the stack. The multi-layered optically active stack is butt or edge coupled to the input waveguide and output waveguide.

Abstract: A method of manufacturing an optoelectronic device including a mode converter. The method has the steps of: on a first silicon-on-insulator (SOI) wafer, manufacturing the optoelectronic device; and either: on a second SOI wafer, manufacturing a mode converter; and bonding the mode converter to the first SOI wafer; or bonding a second SOI wafer to the first SOI wafer to form a combined wafer; and etching a mode converter into the combined wafer.