A wearable computing device includes an electronic display with a configurable brightness level setting, a physiological metric sensor system including a light source configured to direct light into tissue of a user wearing the wearable computing device and a light detector configured to detect light from the light source that reflects back from the user. The device may further include control circuitry configured to activate the light source during a first period, generate a first light detector signal indicating a first amount of light detected by the light detector during the first period, deactivate the light source during a second period, generate a second light detector signal indicating a second amount of light detected by the light detector during the second period, generate a physiological metric based at least in part on the first light detector signal and the second light detector signal, and modify the configurable brightness level setting based on the second light detector signal.

Apparatuses and methods as described herein can be used to help stabilize the gain of a semiconductor-based photomultiplier. In an embodiment, an apparatus can include a semiconductor-based photomultiplier. The apparatus can be configured to inject a first input pulse into the semiconductor-based photomultiplier; determine a revised bias voltage for the semiconductor-based photomultiplier based at least in part on a first output pulse corresponding to the first input pulse and a second output pulse from the semiconductor-based photomultiplier that is obtained at another time as compared to the first output pulse; and adjust a bias voltage for the semiconductor-based photomultiplier to the revised bias voltage. A calibration light source, a temperature sensor, and temperature information are not required to be used for the method.

A method and system, in an optical receiver, includes receiving a first photocurrent from a first photodetector and a second photocurrent from a second photodetector; amplifying the first photocurrent with a first amplifier to provide a first output signal and the second photocurrent with a second amplifier to provide a second output signal; adjusting a frequency response of a first path the first photocurrent and a second path of the second photocurrent; and determining a difference between the adjusted first photocurrent and the adjusted second photocurrent.

A measurement device for a light-emitting device includes a light attenuator, a photometric sphere, and a light detector. The light attenuator includes a first surface and a heat dissipator. A first light that is emitted from the first light-emitting device is incident on the first surface. The first surface is configured to absorb a portion of the first light. The heat dissipator is configured to dissipate heat of the first surface. The photometric sphere has an inner surface to reflect the first light reflected by the first surface. The light detector is configured to receive at least a portion of the first light reflected by the inner surface.

Techniques are disclosed for systems and methods for facilitating pixel readout with partitioned analog-to-digital conversion. A device includes a detector, a capacitor coupled to the detector, a counter circuit coupled to the capacitor, a reset circuit coupled to the capacitor, and a processing circuit. The detector is configured to detect electromagnetic radiation associated with a scene and generate an associated detection signal. The capacitor is configured to, during an integration period, accumulate a voltage based on the detection signal. The counter circuit is configured to, during the integration period, adjust a counter value based on a comparison of the voltage and a reference voltage. The reset circuit is configured to, during the integration period, reset the capacitor based on the comparison. The processing circuit is configured to generate a digital detector output based on the counter value when the integration period has elapsed. Related methods are also provided.

A wearable computing device includes an electronic display with a configurable brightness level setting, a physiological metric sensor system including a light source configured to direct light into tissue of a user wearing the wearable computing device and a light detector configured to detect light from the light source that reflects back from the user. The device may further include control circuitry configured to activate the light source during a first period, generate a first light detector signal indicating a first amount of light detected by the light detector during the first period, deactivate the light source during a second period, generate a second light detector signal indicating a second amount of light detected by the light detector during the second period, generate a physiological metric based at least in part on the first light detector signal and the second light detector signal, and modify the configurable brightness level setting based on the second light detector signal.

An electronic device includes a first superconducting wire (with a first end and a second end) having a first threshold superconducting current. The device includes a second superconducting wire (with a first end and a second end) having a second threshold superconducting current that is less than the first threshold superconducting current. The second end of the first superconducting wire and the second end of the second superconducting wire are coupled to a common voltage node. A resistor is coupled between the first superconducting wire and the second superconducting wire, with a first end of the resistor coupled to the first end of the first superconducting wire and a second end of the resistor coupled to the first end of the second superconducting wire. The device includes a current source coupled with the first superconducting wire, and coupled with a combination of the resistor and the second superconducting wire.

A wearable computing device includes an electronic display with a configurable brightness level setting, a physiological metric sensor system including a light source configured to direct light into tissue of a user wearing the wearable computing device and a light detector configured to detect light from the light source that reflects back from the user. The device may further include control circuitry configured to activate the light source during a first period, generate a first light detector signal indicating a first amount of light detected by the light detector during the first period, deactivate the light source during a second period, generate a second light detector signal indicating a second amount of light detected by the light detector during the second period, generate a physiological metric based at least in part on the first light detector signal and the second light detector signal, and modify the configurable brightness level setting based on the second light detector signal.

An electromagnetic wave detecting apparatus is provided with: a plurality of detecting devices each of which is configured to detect an electromagnetic wave; a voltage applying device configured to apply bias voltage to each of the plurality of detecting devices; an obtaining device configured to obtain a detection signal outputted from each of the plurality of detecting devices; and a setting device configured to set acquisition timing of the detection signal for each of the plurality of detecting devices, on the basis of the bias voltage, which is applied to each of the plurality of detecting devices, and the detection signal of each of the plurality of detecting devices.

Methods and apparatus for a dual mode focal plane array having a background module including a first capacitor to integrate a first signal for a first amount of time, wherein the first signal comprises a background signal, and a signal module including a second capacitor to integrate a second signal for a second amount of time, wherein the second signal comprises a signal of interest and the background signal, wherein the first and second capacitors have impedance values in a first ratio, and wherein the first amount of time and the second amount of time define a second ratio corresponding to the first ratio.