An optical receiver comprises a monolithically integrated pin photodiode (PIN) and transimpedance amplifier (TIA). The TIA comprises InP heterojunction bipolar transistors (HBT) fabricated from a first plurality of layers of an epitaxial layer stack grown on a SI:InP substrate; the PIN is fabricated from a second plurality of layers of the epitaxial layer stack. The p-contact of the PIN is directly connected to the input of the TIA to reduce PIN capacitance CPIN. The TIA capacitance CTIA may be matched to CPIN. Device parameters comprising: a thickness of the absorption layer, window area, and an optional mirror thickness of the PIN; device capacitance CPIN+CTIA; and feedback resistance RF of the TIA; are optimized to performance specifications comprising a specified sensitivity and responsivity at an operational wavelength. This design approach enables cost-effective fabrication an integrated PIN-TIA, for applications such as a 1577 nm receiver for an ONU for 10G-PON.

An apparatus includes a reflective beam shaper configured to receive an input optical signal having a first energy distribution and generate an output optical signal having a second energy distribution different from the first energy distribution. The reflective beam shaper includes multiple reflective mirrors including a first mirror and a second mirror. The first mirror may include a first aspheric reflector configured to reflect the input optical signal as a first intermediate optical signal having a changing energy distribution. The second mirror may include a second aspheric reflector configured to reflect one of the first intermediate optical signal or a second intermediate optical signal as the output optical signal. A third mirror may include a third aspheric reflector configured to reflect the first intermediate optical signal as the second intermediate optical signal having another changing energy distribution.

An apparatus includes a reflective beam shaper configured to receive an input optical signal having a first energy distribution and generate an output optical signal having a second energy distribution different from the first energy distribution. The reflective beam shaper includes multiple reflective mirrors including a first mirror and a second mirror. The first mirror may include a first aspheric reflector configured to reflect the input optical signal as a first intermediate optical signal having a changing energy distribution. The second mirror may include a second aspheric reflector configured to reflect one of the first intermediate optical signal or a second intermediate optical signal as the output optical signal. A third mirror may include a third aspheric reflector configured to reflect the first intermediate optical signal as the second intermediate optical signal having another changing energy distribution.

A method is provided for assessing the quality of an optical transmitter and/or its interoperability with a receiver. The method includes obtaining an optical signal output by an optical transmitter and performing coherent optical-to-electrical detection of the optical signal to produce an in-phase receive signal and a quadrature receive signal. The method further includes a computing device emulating a worst-case configuration of an optical fiber with which the optical transmitter is to be used, based on the in-phase receive signal and the quadrature receive signal to produce a noise contribution associated with the worst-case characteristics of the optical fiber and determining a figure of merit of the optical transmitter based on the noise contribution.

A method is provided for assessing the quality of an optical transmitter and/or its interoperability with a receiver. The method includes obtaining an optical signal output by an optical transmitter and performing coherent optical-to-electrical detection of the optical signal to produce an in-phase receive signal and a quadrature receive signal. The method further includes a computing device emulating a worst-case configuration of an optical fiber with which the optical transmitter is to be used, based on the in-phase receive signal and the quadrature receive signal to produce a noise contribution associated with the worst-case characteristics of the optical fiber and determining a figure of merit of the optical transmitter based on the noise contribution.

An apparatus embodiment includes a remote control interface unit configured to accept an appliance control code carried in a radio frequency signal transmitted from a smart phone, extract the appliance control code from the radio frequency signal, send the extracted appliance control code to an optical frequency interface, and initiate transmission of an optical frequency signal including the appliance control code to an appliance configured to receive signals from an optical remote control.

The present disclosure provides a lithium-ion battery with the configuration where optical signals are output from the light-emitting parts of each unit cell that constitutes the assembled battery, wherein the complexity of wiring can be reduced, and the allowable amount of misalignment can be increased. In a lithium-ion battery (1) in which an assembled battery (50) configured by a plurality of laminated unit cells (30) is accommodated in an outer package (70), each of the unit cell is provided with a light-emitting part (20) that emits light based on the characteristics of the unit cell concerned to output an optical signal, and an optical waveguide (light guide plate) (60) is arranged adjacent or close to a light-emitting surface of the light-emitting part to be a common transmission path of the optical signal from the light-emitting part of the plurality of unit cells.

The present disclosure provides a lithium-ion battery with the configuration where optical signals are output from the light-emitting parts of each unit cell that constitutes the assembled battery, wherein the complexity of wiring can be reduced, and the allowable amount of misalignment can be increased. In a lithium-ion battery (1) in which an assembled battery (50) configured by a plurality of laminated unit cells (30) is accommodated in an outer package (70), each of the unit cell is provided with a light-emitting part (20) that emits light based on the characteristics of the unit cell concerned to output an optical signal, and an optical waveguide (light guide plate) (60) is arranged adjacent or close to a light-emitting surface of the light-emitting part to be a common transmission path of the optical signal from the light-emitting part of the plurality of unit cells.

A signal receiving apparatus includes at least one signal separating apparatus that separates a specific signal from a plurality of received signals. Each of the at least one signal separating apparatus includes a spatial filtering unit that separates at least one equalized signal and a decision signal outputting unit that generates a first decision signal by deciding the equalized signal and outputs the generated first decision signal. The spatial filtering unit separates the at least one equalized signal by multiplying at least the plurality of received signals among the plurality of received signals and either the first decision signal output from the decision signal outputting unit or a second decision signal output from another signal separating apparatus by predetermined weighting coefficients.

In one embodiment, stable and controlled circuit element biasing is provided in a circuit comprising a voltage source operable to output a first voltage, a reference voltage source operable to output a reference voltage, a circuit element biased, during operation, by the first voltage at a first end and by a second voltage at a second end, a voltage controller coupled to the second end of the circuit element, wherein the voltage controller is operable to adjust the second voltage based on a gain output, a gain controller operable to receive the reference voltage as a first input and the second voltage as a second input, wherein the gain controller is operable to generate, at an output of the gain controller, the gain output based on the second voltage and the reference voltage, and a feedback loop that extends from the output of the gain controller, through the voltage controller, and to the second input.