Abstract: A laser comprises a gain medium, and a mirror coupled to the gain medium and comprising a coupler coupled to the gain medium, a phase section coupled to the coupler, a bandpass filter coupled to the phase section, and a comb reflector (CR) coupled to the bandpass filter. A laser chip package comprises a substrate, and a laser coupled to the substrate and comprising a filter comprising a first interferometer with a first transmittance, and a second interferometer with a second transmittance, wherein the filter is configured to provide a filter transmittance based on the first transmittance and the second transmittance, and a comb reflector (CR) coupled to the filter and comprising a ring with a circumference, and a refractive index, wherein the CR is configured to provide a CR reflectivity based on the circumference and the refractive index.

Abstract: A monolithically integrated thermal tunable laser comprising a layered substrate comprising an upper surface and a lower surface, and a thermal tuning assembly comprising a heating element positioned on the upper surface, a waveguide layer positioned between the upper surface and the lower surface, and a thermal insulation layer positioned between the waveguide layer and the lower surface, wherein the thermal insulation layer is at least partially etched out of an Indium Phosphide (InP) sacrificial layer, and wherein the thermal insulation layer is positioned between Indium Gallium Arsenide (InGaAs) etch stop layers.

Abstract: A monolithically integrated thermal tunable laser comprising a layered substrate comprising an upper surface and a lower surface, and a thermal tuning assembly comprising a heating element positioned on the upper surface, a waveguide layer positioned between the upper surface and the lower surface, and a thermal insulation layer positioned between the waveguide layer and the lower surface, wherein the thermal insulation layer is at least partially etched out of an Indium Phosphide (InP) sacrificial layer, and wherein the thermal insulation layer is positioned between Indium Gallium Arsenide (InGaAs) etch stop layers.

Abstract: A laser comprises a front mirror (FM), a gain section coupled to the FM, a phase section coupled to the gain section such that the gain section is positioned between the phase section and the FM, and a back mirror (BM) comprising an interferometer and coupled to the phase section such that the phase section is positioned between the BM and the gain section. A method comprises splitting a first light into a second light and a third light, reflecting the second light to form a second reflected light, reflecting the third light to form a third reflected light, and causing the second reflected light and the third reflected light to interfere and combine to form a combined light to narrow a reflectivity peak spectrum width.

Abstract: A metal-oxide semiconductor (MOS) optical modulator including a doped semiconductor layer having a waveguide structure, a dielectric layer disposed over the waveguide structure of the doped semiconductor layer, a gate region disposed over the dielectric layer, wherein the gate region comprises a transparent electrically conductive material having a refractive index lower than that of silicon, and a metal contact disposed over the gate region. The metal contact, the gate region, and the waveguide structure of the doped semiconductor layer may be vertically aligned with each other.

Abstract: A method of fabricating an edge coupling device and an edge coupling device are provided. The method includes removing a portion of cladding material to form a trench over an inversely tapered silicon waveguide, depositing a material having a refractive index greater than silicon dioxide over remaining portions of the cladding material and in the trench, and removing a portion of the material within the trench to form a ridge waveguide.

Abstract: An apparatus comprising a thick waveguide comprising a first adiabatic tapering from a first location to a second location, wherein the first adiabatic tapering is wider at the first location than at the second location, and a thin slab waveguide comprising a second adiabatic tapering from the first location to the second location, wherein the second adiabatic tapering is wider at the second location than at the first location, and a third adiabatic tapering from the second location to a third location, wherein the third adiabatic tapering is wider at the second location than at the third location, wherein at least a portion of the first adiabatic tapering is adjacent to the second adiabatic tapering, and wherein the first adiabatic tapering and the second adiabatic tapering are separated from each other by a constant gap.

Abstract: An apparatus comprising an optical medium, a power splitter coupled to the optical medium, a first delay line coupled to the power splitter such that the power splitter is positioned between the first delay line and the optical medium, a first comb reflector coupled to the first delay line such that the first delay line is positioned between the first comb reflector and the power splitter, and a second comb reflector coupled to the power splitter but not the first comb reflector and not the first delay line. A method comprising receiving an optical signal, splitting the optical signal into a first split optical signal and a second split optical signal, delaying the first split optical signal, tuning the delayed first split optical signal, tuning the second split optical signal, and delaying the tuned second split optical signal.

Abstract: A metal-oxide-semiconductor (MOS) type semiconductor device, comprising a silicon substrate, a first cathode electrode and a second cathode electrode coupled to the silicon substrate and located on distal ends of the silicon substrate, a poly-silicon (Poly-Si) gate proximally located above the silicon substrate and between the first cathode electrode and the second cathode electrode, wherein the Poly-Si gate comprises a first post extending orthogonally relative to the silicon substrate comprising a first doped silicon slab, a second post extending orthogonally relative to the silicon substrate comprising a second doped silicon slab, wherein the second post is positioned so as to create a width between the first post and the second post, an anode electrode coupled to the first post and the second post and extending laterally from the first post to the second post, and a dielectric layer disposed between the first silicon substrate and the second silicon substrate.

Abstract: An apparatus comprising an optical medium, a power splitter coupled to the optical medium, a first delay line coupled to the power splitter such that the power splitter is positioned between the first delay line and the optical medium, a first comb reflector coupled to the first delay line such that the first delay line is positioned between the first comb reflector and the power splitter, and a second comb reflector coupled to the power splitter but not the first comb reflector and not the first delay line. A method comprising receiving an optical signal, splitting the optical signal into a first split optical signal and a second split optical signal, delaying the first split optical signal, tuning the delayed first split optical signal, tuning the second split optical signal, and delaying the tuned second split optical signal.

Abstract: A laser comprises a front mirror (FM), a gain section coupled to the FM, a phase section coupled to the gain section such that the gain section is positioned between the phase section and the FM, and a back mirror (BM) comprising an interferometer and coupled to the phase section such that the phase section is positioned between the BM and the gain section. A method comprises splitting a first light into a second light and a third light, reflecting the second light to form a second reflected light, reflecting the third light to form a third reflected light, and causing the second reflected light and the third reflected light to interfere and combine to form a combined light to narrow a reflectivity peak spectrum width.

Abstract: A monolithically integrated thermal tunable laser comprising a layered substrate comprising an upper surface and a lower surface, and a thermal tuning assembly comprising a heating element positioned on the upper surface, a waveguide layer positioned between the upper surface and the lower surface, and a thermal insulation layer positioned between the waveguide layer and the lower surface, wherein the thermal insulation layer is at least partially etched out of an Indium Phosphide (InP) sacrificial layer, and wherein the thermal insulation layer is positioned between Indium Gallium Arsenide (InGaAs) etch stop layers.

Abstract: An wave division multiplexed (WDM) optical transmitter is disclosed including a directly modulated laser array and a planar lightwave chip (PLC) having a plurality of OSRs that receive outputs of the laser array and increase the extinction ratio of the received light. An optical multiplexer receives the outputs of the OSRs and couples them to a single output port. The multiplexer has transmission peaks through its ports each having a 0.5 dB bandwidth including the frequency of a laser in the array. The optical multiplexer may be embodied as cascaded Mach-Zehnder interferometers or ring resonators.

Abstract: The frequency chirp modulation response of a directly modulated laser is described using a small signal model that depends on slow chirp amplitude s and slow chirp time constant ?s. The small signal model can be used to derive an inverse response for designing slow chirp compensation means. Slow chirp compensation means include electrical compensation, optical compensation, or both. Slow chirp electrical compensation can be implemented with an LR filter or other RF circuit coupled to a direct modulation source (e.g., a laser driver) and the directly modulated laser. Slow chirp optical compensation can be implemented with an optical spectrum reshaper having a rounded top and relatively large slope (e.g., 1.5-3 dB/GHz). The inverse response can be designed to under-compensate, to produce a flat response, or to over-compensate.

Abstract: A DBR laser, such as a semiconductor DBR laser is disclosed having improved frequency modulation performance. The laser includes a split gain electrode and a tuning electrode. A modulating current encoding a data signal is injected into a first section of the gain electrode whereas a substantially DC bias voltage is imposed on a second section of the gain electrode positioned between the first gain electrode and the tuning electrode. The first and second gain electrodes are electrically isolated from each other and the tuning electrode by a large isolation resistance. In some embodiments, the isolation resistance is generated by forming the electrodes on a P+ layer and removing portions of the P+ layer between adjacent electrodes. Capacitors may couple to one or both of the second gain electrode and the tuning electrode.

Abstract: Use of depletion edge translation as an in cavity phase modulation mechanism in lasers. Aspects of the invention are especially relevant (without limitation) in transmitters for extended reach comprising an intra cavity phase and amplitude modulated laser for generation of a frequency modulated signal and a passive optical spectrum reshaper element, sometimes referred to as a chirp modulated laser. Such techniques may be carried out as disclose herein by adopting predetermined doping profiles and applying predetermined voltage to the laser cavity, and more preferably to a phase section in or adjoining the laser cavity.

Abstract: An wave division multiplexed (WDM) optical transmitter is disclosed including a directly modulated laser array and a planar lightwave chip (PLC) having a plurality of OSRs that receive outputs of the laser array and increase the extinction ratio of the received light. An optical multiplexer receives the outputs of the OSRs and couples them to a single output port. The multiplexer has transmission peaks through its ports each having a 0.5 dB bandwidth including the frequency of a laser in the array. The optical multiplexer may be embodied as cascaded Mach-Zehnder interferometers or ring resonators.

Abstract: A DBR laser, such as a semiconductor DBR laser is disclosed having improved frequency modulation performance. The laser includes a split gain electrode and a tuning electrode. A modulating current encoding a data signal is injected into a first section of the gain electrode whereas a substantially DC bias voltage is imposed on a second section of the gain electrode positioned between the first gain electrode and the tuning electrode. The first and second gain electrodes are electrically isolated from each other and the tuning electrode by a large isolation resistance. In some embodiments, the isolation resistance is generated by forming the electrodes on a P+ layer and removing portions of the P+ layer between adjacent electrodes. Capacitors may couple to one or both of the second gain electrode and the tuning electrode.

Abstract: The present invention relates to a novel compound represented as by formula (I). The present invention also provides a novel strain named as Alternaria alternata var. monosporus, which can produce the compound of formula (I). The inventive strain is cultured in the medium to produce and mass the inventive compound of formula (I) in the strain and the medium. The inventive compound of formula (I) is obtained by recovering and purifying from the mycelia and medium. The compound has strong bioactivity of against cancer, fungi and viruses.

Abstract: The frequency chirp modulation response of a directly modulated laser is described using a small signal model that depends on slow chirp amplitude s and slow chirp time constant ?s. The small signal model can be used to derive an inverse response for designing slow chirp compensation means. Slow chirp compensation means include electrical compensation, optical compensation, or both. Slow chirp electrical compensation can be implemented with an LR filter or other RF circuit coupled to a direct modulation source (e.g., a laser driver) and the directly modulated laser. Slow chirp optical compensation can be implemented with an optical spectrum reshaper having a rounded top and relatively large slope (e.g., 1.5-3 dB/GHz). The inverse response can be designed to under-compensate, to produce a flat response, or to over-compensate.