Abstract: A photonic integrated circuit (PIC) includes a semiconductor substrate with a main bus waveguide disposed within the substrate. Two or more ring lasers are disposed within the substrate and are optically coupled to the main bus waveguide. The ring lasers have a wavelength control mechanism allowing change of a lasers emitted wavelength. A wavelength selective filter is optically coupled to the bus waveguide. A control circuit is electronically coupled to each wavelength control mechanism, and the wavelength selective filter. The control circuit in conjunction with the selective filter allows monitoring of a ring laser's wavelength on the main bus waveguide. Based on a determined wavelength, the control circuit may change a ring laser wavelength to a desired wavelength to achieve a desired wavelength spacing for each of the ring lasers. The PIC may be integrated as a coarse wave-length division multiplexing (CWDM) transmit module.

Abstract: A laser includes a traveling wave laser cavity with an active section, a pulse stretcher, and a pulse compressor. The pulse stretcher is coupled to the waveguide before the active section and the pulse compressor is coupled to the waveguide after the active section.

Abstract: A device comprises a substrate, a sacrificial material layer over the substrate, a first solid-state material layer over the sacrificial layer, a dielectric layer over solid-state material layer, and a second solid-state material layer over the dielectric layer. The sacrificial material layer may have an airgap, the solid-state material layer may comprise a structure over the airgap and may be separated from a bulk portion of the first material layer by trenches, where the trenches extend to the airgap.

Abstract: A multilayer device includes a substrate and a first layer disposed on the substrate. A trench extends through one or both of the substrate and the first layer. The trench has a first sidewall spaced apart from a second sidewall, each sidewall extending from an upper surface of the substrate to a lower surface of the first layer. An optically active region is disposed on the first layer overlying the trench, such that at least a portion of the optically active region is located within a set of lines corresponding to the sidewalls of the trench.

Abstract: Coupling modulation of an optical resonator employs a variable modal index to provide modulation of optical signal coupling. A coupling-modulated optical resonator includes an optical resonator having a coupled portion and a bus waveguide having a modulation section adjacent to and coextensive with and separated by a gap from the coupled portion. The modulation section is to modulate coupling of an optical signal between the optical resonator and the bus waveguide according to a variable difference between a modal index of the bus waveguide modulation section and a modal index of the optical resonator coupled portion.

Abstract: According to an example of the present disclosure a semiconductor laser diode includes a layer of graphene between an active laser region and a semiconductor substrate structure. The semiconductor laser diode may further include a first pair of electrodes to apply a potential difference across the active laser region and a second pair of electrodes to apply a potential difference across the layer of graphene.

Abstract: Examples disclosed herein relate to optical driver circuits. In some of the disclosed examples, an optical driver circuit includes a pre-driver circuit and a main driver circuit. The pre-driver circuit may include a pattern generator and at least one serializer to generate a main modulation signal and an inverted delayed modulation signal. The main driver circuit may include a level controller to control amplitudes of pre-emphasis on rising and falling edges of a modulation signal output and an equalization controller to transition the modulation signal output from the pre-emphasis amplitudes to main modulation amplitudes using the inverted delayed modulation signal.

Abstract: A laser includes a traveling wave laser cavity with an active section, a pulse stretcher, and a pulse compressor. The pulse stretcher is coupled to the waveguide before the active section and the pulse compressor is coupled to the waveguide after the active section.

Abstract: An example system for multi-wavelength optical signal splitting is disclosed. The example disclosed herein comprises a first splitter, a second splitter, and a modulator. The system receives a multi-wavelength optical signal and an electrical signal, wherein the multi-wavelength optical signal comprises a plurality of optical wavelengths and has a power level. The first splitter is to split the plurality of optical wavelengths into a plurality of optical wavelength groups. The second splitter is to split the multi-wavelength optical signal or the plurality of optical wavelength groups into a plurality of lower power signal groups. The modulator is to encode the electrical signal into the plurality of optical wavelength groups, the plurality of lower power signal groups, or a combination thereof.

Abstract: An example method of manufacturing a semiconductor device. A first wafer may be provided that includes a first layer that contains quantum dots. A second wafer may be provided that includes a buried dielectric layer and a second layer on the buried dielectric layer. An interface layer may be formed on at least one of the first layer and the second layer, where the interface layer may be an insulator, a transparent electrical conductor, or a polymer. The first wafer may be bonded to the second wafer by way of the interface layer.

Abstract: Examples herein relate to devices having substrates with selective airgap regions for mitigating defects resulting from heteroepitaxial growth of device materials. An example device may include a first semiconductor layer disposed on a substrate. The first semiconductor layer may have a window cut through a face, where etching a selective airgap region on the substrate is enabled via the window. A second semiconductor layer may be heteroepitaxially grown on the face of the first semiconductor layer so that at least a portion of the second semiconductor layer is aligned over the selective air gap region.

Abstract: Compact photonics platforms and methods of forming the same are provided. An example of a compact photonics platform includes a layered structure having an active region along a longitudinal axis, a facet having an angle no less than a critical angle formed at at least one longitudinal end of the active region, and a waveguide having at least one grating coupler positioned in alignment with the angled facet to couple light out to or in from the waveguide.

Abstract: Examples disclosed herein relate to optical driver circuits. In some of the disclosed examples, an optical driver circuit includes a pre-driver circuit and a main driver circuit. The pre-driver circuit may include a pattern generator and at least one serializer to generate a main modulation signal and an inverted delayed modulation signal. The main driver circuit may include a level controller to control amplitudes of pre-emphasis on rising and falling edges of a modulation signal output and an equalization controller to transition the modulation signal output from the pre-emphasis amplitudes to main modulation amplitudes using the inverted delayed modulation signal.

Abstract: According to an example of the present disclosure a direct bandgap (DBG) semiconductor structure is bonded to an assembly comprising a silicon photonics (SiP) wafer and a complementary metal-oxide-semiconductor (CMOS) wafer. The SiP wafer includes photonics circuitry and the CMOS wafer includes electronic circuitry. The direct bandgap (DBG) semiconductor structure is optically coupled to the photonics circuitry.

Abstract: A multilayer device includes a substrate having a trench extending along a first surface of the substrate. A first layer disposed on the first surface of the substrate, the first layer comprising a given surface and another surface. A dielectric layer is formed between the given surface of the first layer and the first surface of the substrate. An active region disposed on the other surface of the first layer overlying the trench, wherein at least a portion of the active region resides substantially above a region defined by the trench.

Abstract: An example method of manufacturing a semiconductor device. A first wafer may be provided that includes a first layer that contains quantum dots. A second wafer may be provided that includes a buried dielectric layer and a second layer on the buried dielectric layer. An interface layer may be formed on at least one of the first layer and the second layer, where the interface layer may be an insulator, a transparent electrical conductor, or a polymer. The first wafer may be bonded to the second wafer by way of the interface layer.

Abstract: Examples disclosed herein relate to multi-wavelength semiconductor comb lasers. In some examples disclosed herein, a multi-wavelength semiconductor comb laser may include a waveguide included in an upper silicon layer of a silicon-on-insulator (SOI) substrate. The comb laser may include a quantum dot (QD) active gain region above the SOI substrate defining an active section in a laser cavity of the comb laser and a dispersion tuning section included in the laser cavity to tune total cavity dispersion of the comb laser.

Abstract: An example device in accordance with an aspect of the present disclosure includes a ring waveguide and bus waveguide. The ring waveguide has a first coupled portion associated with a first modal index, and the bus waveguide includes a second coupled portion associated with a second modal index. The second coupled portion is evanescently coupleable to the first coupled portion. A laser outcoupling and associated lasing output of the device is variable based on varying a difference between the first modal index and the second modal index to vary coupling between the first coupled portion and the second coupled portion, without varying modal indices of non-coupled portions of the ring waveguide and bus waveguide.

Abstract: Compact photonics platforms and methods of forming the same are provided. An example of a compact photonics platform includes a layered structure having an active region along a longitudinal axis, a facet having an angle no less than a critical angle formed at at least one longitudinal end of the active region, and a waveguide having at least one grating coupler positioned in alignment with the angled facet to couple light out to or in from the waveguide.

Abstract: An example device in accordance with an aspect of the present disclosure includes a first layer and a second layer to be bonded to the first layer. The first and second layers are materials that generate gas byproducts when bonded, and the first and/or second layers is/are compatible with photonic device operation based on a separation distance. At least one bonding interface layer is to establish the separation distance for photonic device operation, and is to prevent gas trapping and to facilitate bonding between the first layer and the second layer.