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.

Abstract: A polarity-independent optical receiver is constructed so that the bias voltage applied to the optical receiver may be applied in a polarity-independent manner. The polarity-independent optical receiver is also constructed in a balanced arrangement, thus providing the ability to effectively suppress common-mode intensity noise present at the optical receiver. The polarity-independent optical receiver may advantageously be fabricated using metal-semiconductor-metal (MSM) technology.

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.