Sandia Corporation

National Technology & Engineering Solutions of Sandia, LLC

Other

Erik J Skogen

Gregory A Vawter

Anna Tauke-Pedretti

James W Raring

G Allen Vawter

Weng W Chow

Charles Alford

Junoh Choi

A semiconductor optical amplifier (SOA) with a variable optical confinement factor I' along the length of the device is disclosed. At the input end of the SOA, the optical confinement is high as an optical core is adjacent an optical gain layer, resulting in a high-gain region that rapidly increases the optical signal power. In the central portion of the SOA, the optical confinement is continuously reduced as the optical core is tapered away from the optical gain layer, thereby lowering the gain, but increasing the output saturation power. Near the output end of the SOA, the optical confinement factor is held constant, providing a length of additional gain, thereby further increasing the output power. The SOA may optionally include a spot-size converter region to focus the output optical signal.

Continuously variable optical confinement for optical amplifiers

Monochromatic photosensitive devices (MPDs) having series connected photosensitive diode cell arrays in two configurations are disclosed. The MPDs employ a protection diode to bypass either one or multiple photosensitive diodes in each photosensitive diode cell should a photosensitive diode fail as an open circuit or become blocked from the monochromatic light. The protection diode is vertically (epitaxial growth direction) integrated with a photosensitive diode layer structure during epitaxial growth, thereby permitting monolithic fabrication of the one or multiple photosensitive diode cells. The bulk of the one or multiple photosensitive diodes are formed of a material having a bandgap corresponding to the wavelength of the monochromatic light, while the protection diodes are formed of a material having a bandgap greater than the wavelength of the monochromatic light. The monochromatic light passes through the protection diode before being absorbed by the one or multiple photosensitive diodes.

Epitaxially integrated protection diodes for monochromatic photosensitive diodes

A hybrid-integrated series/parallel-connected photovoltaic diode array employs 10s-to-100s of single-wavelength III-V compound semiconductor photodiodes in an array bonded onto a transparent optical plate through which the array is illuminated by monochromatic light. The power-by-light system receiver enables high-voltage, up to 1000s of volts, optical transmission of power to remote electrical systems in harsh environments.

Photovoltaic array for a power-by-light system

An electroabsorption modulator incorporates waveguiding regions along the length of the modulator that include quantum wells where at least two of the regions have quantum wells with different bandgaps. In one embodiment of the invention, the regions are arranged such that the quantum wells have bandgaps with decreasing bandgap energy along the length of the modulator from the modulator's input to its output. The bandgap energy of the quantum wells may be decreased in discrete steps or continuously. Advantageously, such an arrangement better distributes the optical absorption as well as the carrier density along the length of the modulator. Further advantageously, the modulator may handle increased optical power as compared with prior art modulators of similar dimensions, which allows for improved link gain when the optical modulator is used in an analog optical communication link.

Electroabsorption optical modulator

The present invention relates to optical vias to optically connect multilevel optical circuits. In one example, the optical via includes a surface plasmon polariton waveguide, and a first optical waveguide formed on a first substrate is coupled to a second optical waveguide formed on a second substrate by the surface plasmon polariton waveguide. In some embodiments, the first optical waveguide includes a transition region configured to convert light from an optical mode to a surface plasmon polariton mode or from a surface plasmon polariton mode to an optical mode.

Plasmon-assisted optical vias for photonic ASICS

The present invention includes a high-speed, high-saturation power detector (e.g., a photodiode) compatible with a relatively simple monolithic integration process. In particular embodiments, the photodiode includes an intrinsic bulk absorption region, which is grown above a main waveguide core including a number of quantum wells (QWs) that are used as the active region of a phase modulator. The invention also includes methods of fabricating integrated photodiode and waveguide assemblies using a monolithic, simplified process.

Guided-wave photodiode using through-absorber quantum-well-intermixing and methods thereof

An optical sampler includes a first and second 1&#xd7;n optical beam splitters splitting an input optical sampling signal and an optical analog input signal into n parallel channels, respectively, a plurality of optical delay elements providing n parallel delayed input optical sampling signals, n photodiodes converting the n parallel optical analog input signals into n respective electrical output signals, and n optical modulators modulating the input optical sampling signal or the optical analog input signal by the respective electrical output signals, and providing n successive optical samples of the optical analog input signal. A plurality of output photodiodes and eADCs convert the n successive optical samples to n successive digital samples. The optical modulator may be a photodiode interconnected Mach-Zehnder Modulator. A method of sampling the optical analog input signal is disclosed.

Parallel optical sampler

Semiconductor light-emitting devices; methods of forming semi-conductor light emitting devices, and methods of operating semi-conductor light emitting devices are provided. A semiconductor light-emitting device includes a first laser section monolithically integrated with a second laser section on a common substrate. Each laser section has a phase section, a gain section and at least one distributed Bragg reflector (DBR) structure. The first laser section and the second laser section are optically coupled to permit optical feedback therebetween. Each phase section is configured to independently tune a respective one of the first laser section and second laser section relative to each other.

Mutually injection locked lasers for enhanced frequency response

An optical set-reset (SR) latch is formed from a first electroabsorption modulator (EAM), a second EAM and a waveguide photodetector (PD) which are arranged in an optical and electrical feedback loop which controls the transmission of light through the first EAM to latch the first EAM in a light-transmissive state in response to a Set light input. A second waveguide PD controls the transmission of light through the second EAM and is used to switch the first EAM to a light-absorptive state in response to a Reset light input provided to the second waveguide PD. The optical SR latch, which may be formed on a III-V compound semiconductor substrate (e.g. an InP or a GaAs substrate) as a photonic integrated circuit (PIC), stores a bit of optical information and has an optical output for the logic state of that bit of information.

Optical set-reset latch

An optical NOR gate is formed from two pair of optical waveguide devices on a substrate, with each pair of the optical waveguide devices consisting of an electroabsorption modulator electrically connected in series with a waveguide photodetector. The optical NOR gate utilizes two digital optical inputs and a continuous light input to provide a NOR function digital optical output. The optical NOR gate can be formed from III-V compound semiconductor layers which are epitaxially deposited on a III-V compound semiconductor substrate, and operates at a wavelength in the range of 0.8-2.0 &#x3bc;m.

Optical NOR gate

An optical NAND gate is formed from two pair of optical waveguide devices on a substrate, with each pair of the optical waveguide devices consisting of an electroabsorption modulator and a photodetector. One pair of the optical waveguide devices is electrically connected in parallel to operate as an optical AND gate; and the other pair of the optical waveguide devices is connected in series to operate as an optical NOT gate (i.e. an optical inverter). The optical NAND gate utilizes two digital optical inputs and a continuous light input to provide a NAND function output. The optical NAND gate can be formed from III-V compound semiconductor layers which are epitaxially deposited on a III-V compound semiconductor substrate, and operates at a wavelength in the range of 0.8-2.0 &#x3bc;m.

Optical NAND gate

An optical analog-to-digital converter (ADC) is disclosed which converts an input optical analog signal to an output optical digital signal at a sampling rate defined by a sampling optical signal. Each bit of the digital representation is separately determined using an optical waveguide interferometer and an optical thresholding element. The interferometer uses the optical analog signal and the sampling optical signal to generate a sinusoidally-varying output signal using cross-phase-modulation (XPM) or a photocurrent generated from the optical analog signal. The sinusoidally-varying output signal is then digitized by the thresholding element, which includes a saturable absorber or at least one semiconductor optical amplifier, to form the optical digital signal which can be output either in parallel or serially.

Growing community of inventors

Albuquerque, NM, United States of America

Erik J Skogen