Embodiments of the present disclosure include optical transmitters and transceivers with improved reliability. In some embodiments, the optical transmitters are used in network devices, such as in conjunction with a network switch. In one embodiment, lasers are operated at low power to improve reliability and power consumption. The output of the laser may be modulated by a non-direct modulator and received by integrated optical components, such as a modulator and/or multiplexer. The output of the optical components may be amplified by a semiconductor optical amplifier (SOA). Various advantageous configurations of lasers, optical components, and SOAs are disclosed. In some embodiments, SOAs are configured as part of a pluggable optical communication module, for example.

Methods of manufacturing heterojunction bipolar transistors are described herein. An exemplary method can include providing an emitter/base stack comprising a substrate, a base over the substrate, and/or an emitter over the base. The exemplary method further can include forming a collector. The exemplary method also can include wafer bonding the base to the collector. Other embodiments are also disclosed herein.

A photonic integrated circuit (PIC) includes a semiconductor substrate, one or more passive components, and one or more active components. The one or more passive components are fabricated on the semiconductor substrate, wherein the passive components are fabricated in a III-V type semiconductor layer. The one or more active components are fabricated on top of the one or more passive components, wherein optical signals are communicated between the one or more active components via the one or more passive components.

Disclosed is a laser device. The laser device includes a substrate, a pump light source which is disposed on the substrate and provided with a light emitting layer configured to generate pump light, and an upper waveguide which is disposed above the pump light source in a first direction and provided with an upper resonator configured to allow laser light to be generated and resonate by using the pump light.

A beam steering apparatus includes a substrate; at least one light source provided on the substrate; a first waveguide configured to transmit a first light beam radiated from the at least one light source; at least one beam splitter configured to split the first light beam transmitted by the first waveguide to obtain a second light beam; a second waveguide configured to receive the second light beam; and a quantum dot optical amplifier provided on the second waveguide and comprising a barrier layer, a quantum dot layer, and a wetting layer, the quantum dot optical amplifier being configured to modulate a phase of the second light beam, and to amplify an intensity of the second light beam.

Embodiments of the present disclosure are directed to a semiconductor optical amplifier including a semiconductor-based gain medium configured to receive a drive current and a variable-width waveguide coupled to the in the semiconductor-based gain medium, the variable-width waveguide including a plurality of narrow width regions and a plurality of wide width regions positioned alternately along a longitudinal axis of the waveguide. The variable-width waveguide further includes a plurality of transition regions having an adiabatically varying widths. Each transition region connects adjacent ones of the plurality of narrow width and width regions and the waveguide has a reduced drive current density in the plurality of wide width regions relative to the drive current density in the plurality of narrow width regions.

A semiconductor optical amplifier (SOA) receives a multiwavelength input optical signal and amplifies the multiwavelength input optical signal to generate an amplified multiwavelength optical signal. A waveguide is coupled to receive the amplified multiwavelength optical signal. The waveguide includes an enhanced chromatic dispersion segment configured to increase chromatic dispersion experienced by the multiwavelength optical signal as the multiwavelength optical signal propagates through the waveguide and is amplified by the SOA. This increase in chromatic dispersion reduces noise, such as four-wave mixing noise, in the amplified multiwavelength optical signal.

A distributed feedback (DFB) laser that includes a substrate comprising a first surface and a second surface, wherein the substrate comprises silicon; a plurality of shallow trench isolations (STIs) located over the second surface of the substrate; a grating region located over the plurality of STIs and the substrate, wherein the grating region comprises a III-V semiconductor material; a non-intentional doping (NID) region located over the grating region; and a contact region located over the NID region.

Disclosed herein is a semiconductor device comprising: a silicon substrate; a germanium layer; and a buffer layer comprised of at least one layer of III-V compound, formed directly on silicon; at least one layer containing III-V compound quantum dots wherein one or more facets are formed using focused ion beam etching such that the angle between the plane of the facet is normal to the plane of growth.

A combination of microvalves and waveguides may enable the creation of reconfigurable on-chip light sources compatible with planar sample preparation and particle sensing architecture using either single-mode or multi-mode interference (MMI) waveguides. A first type of light source is a DFB laser source with lateral gratings created by the light valves. Moreover, feedback for creating a narrowband light source does not have to be a DFB grating in the active region. A DBR configuration (Bragg mirrors on one or both ends of the active region) or simple mirrors at the end of the cavity can also be used. Alternately, ring resonators may be created using a valve coupled to a bus waveguide where the active gain medium is either incorporated in the ring or inside an enclosed fluid. The active light source may be activated by moving a fluid trap and/or a solid-core optical component defining its active region.