Optical Sensor Bias Control for Wide Dynamic Range Detection
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Solution Overview
Problem
Existing optical sensors have a limited dynamic range due to fixed photodetector characteristics, which restricts their ability to operate effectively across a wide range of distances and ambient light levels, requiring either optical or structural adjustments that compromise sensitivity or complexity.
Innovation Solution
The optical sensor employs multiple photodetectors with varying excess bias voltages, allowing for electrical adjustment of their dynamic range, enabling operation across a broader range of incident photon rates without sacrificing sensitivity or increasing structural complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the aperture of the photodetector is adjusted to control dynamic range, then the dynamic range is improved, but the sensitivity is compromised
Solution Approach 1:
The patent changes the electrical parameter (excess bias voltage) of the photodetector to control dynamic range instead of changing the optical parameter (aperture). By varying the excess bias voltage, the photodetector's response to incident photons is modulated, allowing dynamic range adjustment without affecting the physical aperture and thus preserving sensitivity.
2Adaptability or versatility
If optical adjustments are made to control dynamic range, then the dynamic range is improved, but the structural complexity increases
Solution Approach 1:
The patent replaces the mechanical/optical adjustment system (aperture control) with an electrical control system (bias voltage adjustment). This substitution eliminates the need for moving parts or complex optical mechanisms, reducing structural complexity while maintaining the ability to control dynamic range through electrical parameters.
3Device complexity
If a single photodetector with fixed characteristics is used, then the device complexity is reduced, but the dynamic range is limited
Solution Approach 1:
The patent introduces dynamic control of the photodetector's operating parameters by varying the excess bias voltage over time. This allows a single photodetector to adapt its characteristics dynamically, effectively covering a wide dynamic range without requiring multiple photodetectors with different fixed characteristics, thus maintaining low structural complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the overall dynamic range of the optical sensor, allowing it to detect objects at various distances and under different ambient light conditions with improved sensitivity and reduced complexity.
Implementation Method 1
at least one photodetector configured to be reverse biased at a voltage exceeding a breakdown voltage
Implementation Method 2
reverse biased at a voltage exceeding a breakdown voltage by an excess bias voltage. In this way, a carrier generated by a single photon can be injected into a depletion region and can cause a self-sustaining avalanche
Data Source
AI summary
An optical sensor includes at least one photodetector configured to be reverse biased at a voltage exceeding a breakdown voltage by an excess bias voltage. At least one control unit is configured to adjust the reverse bias of the at least one photodetector. A method of operating an optical sensor is also disclosed.