Abstract: A magnetometer includes a resonant atomic medium, a photonic crystal surface emitting laser (PCSEL), and a light detector. The resonant atomic medium includes color centers or other dopants that form vacancies that fluoresce light when excited by an excitation light having an excitation wavelength. Characteristics of the fluoresced light are dependent upon a magnetic field applied to the resonant atomic medium. The PCSEL is configured to develop the excitation light having the excitation wavelength of the vacancies and direct the excitation light into the resonant atomic medium. The light detector is configured to receive the fluoresced light and generate a measurement signal indicative of the fluoresced light and the magnetic field applied to the resonant atomic medium.

Abstract: An example optical device may have a surface-emitting laser structure that includes an active region configured to generate output light, a first distributed Bragg reflector (DBR) disposed below the active region, a second distributed Bragg reflector (DBR) disposed above the active region, a modulation structure that includes electroabsorption material, configured to modulate the output light in response to an applied bias, wherein the modulation structure is disposed within or adjacent to at least one of the first DBR and the second DBR. The electroabsorption material may include graphene or graphene-based composite material. An example method for modulating the output light may include generating a continuous-wave (CW) light in the active region, and then modulating the CW light by the modulation structure, via a bias-dependent absorption provided by the electroabsorption material.

Abstract: This disclosure describes a photon-photon resonance photonic crystal surface-emitting laser (PPR PCSEL) operable in high-speed applications. The PPR PCSEL comprises a first photonics crystal section and a second photonics crystal section located at along the same fabrication layer. The first photonics crystal section is operable to out-couple light vertically. The second photonics crystal section is operable to produce a photon-photon resonance. The etched pattern in the first photonics crystal section is different than the etched pattern in the second photonics crystal section.

Abstract: An optical signal generation system for multi-level optical signal generation using binary keying comprises an array of light sources, a control circuit, and an optical coupling mechanism. The system may be operable to configure, using the control circuit, each of the light sources in the array of light sources in a HIGH or LOW state base on a received input signal to generate a plurality of optical output signals. The plurality of optical output signals may be communicated to the optical coupling mechanism and combined into a single optical signal thereby generating a multi-level output signal representative of the received input signal. The multi-level output signal may comprise a Pulse Amplitude Modulated (PAM) equivalent signal. The array of light sources may comprise vertical cavity surface emitting lasers (VCSELs), edge-emitting lasers, or light emitting diodes (LEDs).

Abstract: This disclosure describes an optical communication system for coupling light, via VCSEL or PCSEL, into a multilayer waveguide. The optical communication system comprises a plurality of emitters, a semi-insulating (SI) substrate, a plurality of electrical contacts, a plurality of waveguides, and a diffractive optical coupling system. The SI substrate supports the plurality of emitters. The plurality of electrical contacts are configured to individually modulate each emitter. The plurality of waveguides and the plurality of emitters are separated by an air gap. The diffractive optical coupling system is configured to direct emitted light from the plurality of emitters into the waveguides.

Abstract: A magnetometer includes a resonant atomic medium, a photonic crystal surface emitting laser (PCSEL), and a light detector. The resonant atomic medium includes color centers or other dopants that form vacancies that fluoresce light when excited by an excitation light having an excitation wavelength. Characteristics of the fluoresced light are dependent upon a magnetic field applied to the resonant atomic medium. The PCSEL is configured to develop the excitation light having the excitation wavelength of the vacancies and direct the excitation light into the resonant atomic medium. The light detector is configured to receive the fluoresced light and generate a measurement signal indicative of the fluoresced light and the magnetic field applied to the resonant atomic medium.

Abstract: This disclosure describes an integrated compound semiconductor co-packaged optics (CCPO) device. The CCPO device has a photonic integrated circuit (PIC) and an electronic integrated circuit (EIC) mounted on a common package substrate. The PIC has a modulator array and a photodetector (PD) array fabricated in GaAs and/or InP. In some configurations the PIC also has an amplifier array fabricated in GaAs and/or InP. The CCPO design reduces loss and signal integrity issues that are typically present when the PIC and EIC are on separate substrates.

Abstract: This disclosure describes a bottom surface emitting vertical cavity surface emitting laser (BSE VCSEL) with a lithographically defined aperture. The BSE VCSEL may be oxide-free. Two contacts are located above a substrate. An aperture and one or more active regions are located between two DBRs. A first contact is coupled to the substrate and the first DBR, which is below the aperture. A second contact is coupled to the second DBR, which is above the aperture.

Abstract: Sensors with an addressable depth range and/or field of view are disclosed. Computing devices with such sensors are also disclosed. A sensor may include multiple output couplers that are positioned at different distances from a receiver. Through selective enabling of the output couplers, light or other radiation generated by a transmitter may be directed toward the output couplers and selectively emitted from the sensor at different distances from the transmitter. Such selective emitting may adjust a depth range and/or field of view of the sensor. A computing device may include a single sensor that is used across applications and/or processes having different needs with regard to depth range and/or field of view.

Abstract: This disclosure describes a red-green-blue (RGB) vertical-cavity surface-emitting laser (VCSEL) array. Each VCSEL in the VCSEL array has a grating, one or more active regions and two distributed Bragg reflectors. Each VCSEL corresponds to either red, green or blue wavelengths. The number of active regions in each VCSEL may be based on the color emitted.

Abstract: An example embodiment includes a fiber optic integrated circuit (IC). The fiber optic IC includes an integrated power supply. The integrated power supply includes a filter, an active switch, and a pulse width modulator (“PWM”). The filter is configured to convert a signal to an output signal of the integrated power supply. The active switch is configured to control introduction of the signal to the filter. The PWM is configured to generate a PWM output signal that triggers the active switch.

Abstract: A method of transmitting data may include receiving feedback information that includes effective channel bandwidths, signal-to-noise ratios (SNRs) associated with multiple optical channels on an optical link, and individual SNRs associated with subcarriers on each optical channel. The method may include determining multiple subcarrier power allocation schemes based on the feedback information. Each subcarrier power allocation scheme may be associated with a corresponding optical channel from the multiple optical channels and may be configured to allocate a signal power among subcarriers configured to transmit on the corresponding optical channel. The method may include determining, based on the feedback information, an optical power allocation scheme configured to allocate an optical power among the multiple optical channels. The method may include transmitting data on the multiple optical channels based on the multiple subcarrier power allocation schemes and the optical power allocation scheme.

Abstract: An example embodiment includes a fiber optic integrated circuit (IC). The fiber optic IC includes an integrated power supply. The integrated power supply includes a filter, an active switch, and a pulse width modulator (“PWM”). The filter is configured to convert a signal to an output signal of the integrated power supply. The active switch is configured to control introduction of the signal to the filter. The PWM is configured to generate a PWM output signal that triggers the active switch.

Abstract: A method of transmitting data may include receiving feedback information that includes effective channel bandwidths, signal-to-noise ratios (SNRs) associated with multiple optical channels on an optical link, and individual SNRs associated with subcarriers on each optical channel. The method may include determining multiple subcarrier power allocation schemes based on the feedback information. Each subcarrier power allocation scheme may be associated with a corresponding optical channel from the multiple optical channels and may be configured to allocate a signal power among subcarriers configured to transmit on the corresponding optical channel. The method may include determining, based on the feedback information, an optical power allocation scheme configured to allocate an optical power among the multiple optical channels. The method may include transmitting data on the multiple optical channels based on the multiple subcarrier power allocation schemes and the optical power allocation scheme.

Abstract: An example embodiment includes a fiber optic integrated circuit (IC). The fiber optic IC includes an integrated power supply. The integrated power supply includes a filter, an active switch, and a pulse width modulator (“PWM”). The filter is configured to convert a signal to an output signal of the integrated power supply. The active switch is configured to control introduction of the signal to the filter. The PWM is configured to generate a PWM output signal that triggers the active switch.

Abstract: The extraction efficiency of a light emitting device can be improved by making the absorbing device layers as thin as possible. The internal quantum efficiency decreases as the device layers become thinner. An optimal active layer thickness balances both effects. An AlGaInP LED includes a substrate and device layers including an AlGaInP lower confining layer of a first conductivity type, an AlGaInP active region of a second conductivity type, and an AlGaInP upper confining layer of a second conductivity type. The absorbance of the active region is at least one fifth of the total absorbance in the light-emitting device. The device optionally includes at least one set-back layers of AlGaInP interposing one of confining layer and active region. The p-type upper confining layer may be doped with oxygen improve the reliability.

Abstract: A light emitting device in accordance with an embodiment of the present invention includes a first semiconductor layer of a first conductivity type having a first surface, and an active region formed overlying the first semiconductor layer. The active region includes a second semiconductor layer which is either a quantum well layer or a barrier layer. The second semiconductor layer is formed from a semiconductor alloy having a composition graded in a direction substantially perpendicular to the first surface of the first semiconductor layer. The light emitting device also includes a third semiconductor layer of a second conductivity type formed overlying the active region.

Abstract: A light-emitting semiconductor device comprises a III-Nitride active region and a III-Nitride layer formed proximate to the active region and having a thickness that exceeds a critical thickness for relaxation of strain in the III-Nitride layer. The III-Nitride layer may be a carrier confinement layer, for example. In another aspect of the invention, a light-emitting semiconductor device comprises a III-Nitride light emitting layer, an InxAlyGa1-x-yN (0?x?1, 0?y?1, x+y?1), and a spacer layer interposing the light emitting layer and the InxAlyGa1-x-yN layer. The spacer layer may advantageously space the InxAlyGa1-x-yN layer and any contaminants therein apart from the light emitting layer. The composition of the III-Nitride layer may be advantageously selected to determine a strength of an electric field in the III-Nitride layer and thereby increase the efficiency with which the device emits light.

Abstract: The extraction efficiency of a light emitting device can be improved by making the absorbing device layers as thin as possible. The internal quantum efficiency decreases as the device layers become thinner. An optimal active layer thickness balances both effects. An AlGaInP LED includes a substrate and device layers including an AlGaInP lower confining layer of a first conductivity type, an AlGaInP active region of a second conductivity type, and an AlGaInP upper confining layer of a second conductivity type. The absorbance of the active region is at least one fifth of the total absorbance in the light-emitting device. The device optionally includes at least one set-back layers of AlGaInP interposing one of confining layer and active region. The p-type upper confining layer may be doped with oxygen improve the reliability.

Abstract: The photoconductive switch comprises a first confinement layer, a second confinement layer, a photoconductive layer that includes a doped sub-layer and an undoped sub-layer, a first electrode and a second electrode. The first confinement layer is a layer of a first semiconductor material having a first band-gap energy and a first conductivity type. The second confinement layer is a layer of a second semiconductor material having a second band-gap energy. The photoconductive layer is a layer of a third semiconductor material having a third band-gap energy and a second conductivity type, opposite to the first conductivity type. The photoconductive layer is sandwiched between the first confinement layer and the second confinement layer, and the third band-gap energy is less than the first and second band-gap energies. In the photoconductive layer, the doped sub-layer is in contact with the first confinement layer, and the undoped sub-layer is adjacent the second confinement layer.