Integrated Photodiode Array for Weak Optical Signal Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional laser-based measurement systems face difficulties in detecting and processing very small signals due to parasitic effects in discrete circuit components, leading to the need for increased laser power and complex signal processing, which can be inefficient and costly.
Innovation Solution
The use of mixed-signal processing methods implemented with integrated circuit technologies, specifically through active pixel networks and delta-sigma modulation, enables the detection and digitization of weak optical signals, reducing the required laser power and optimizing signal processing with minimal software and hardware requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If discrete circuit components are used in laser-based measurement systems, then the circuit components are simple and inexpensive, but parasitic effects make it difficult to detect and process very small signals
Solution Approach 1:
The patent replaces discrete circuit components with integrated circuit technologies, specifically using photodiodes integrated with signal processing circuits on a single chip. This substitution eliminates the parasitic effects associated with discrete component interconnections while maintaining manufacturing simplicity through standard integrated circuit fabrication processes.
Solution Approach 2:
The patent combines multiple functions (photodetection, signal amplification, and processing) into a single integrated circuit device. The photodiode array is directly integrated with readout circuits and signal processing elements, merging what were previously separate discrete components into one unified structure that eliminates interconnection parasitics.
2Measurement precision
If increased laser power is used to overcome discrete circuit limitations, then signal detection capability improves, but system power consumption and complexity increase
Solution Approach 1:
The patent replaces the need for high laser power by substituting discrete circuit limitations with integrated circuit capabilities. The integrated photodiode array with built-in signal processing can detect and amplify weak signals directly at the sensor level, eliminating the need to increase laser power to overcome discrete circuit parasitic effects.
Solution Approach 2:
The patent performs signal amplification and processing preliminary actions directly at the photodetector level before signals are transmitted for further processing. The integrated circuits amplify weak photodiode currents immediately upon generation, preventing signal degradation and eliminating the need for subsequent high-power signal boosting.
3Measurement precision
If larger arrays of photodiodes are used to detect small signals, then detection capability improves, but device size and interconnection complexity increase
Solution Approach 1:
The patent merges the photodiode array with readout circuits and signal processing elements into a single integrated circuit structure. This integration eliminates the complex interconnections between separate photodiodes and external processing circuits, as all elements are fabricated together on the same substrate with minimal interconnect requirements.
Solution Approach 2:
The patent replaces the mechanical interconnection structure of discrete photodiode arrays with an integrated circuit architecture where electrical connections are formed through standard semiconductor fabrication processes. This substitution dramatically reduces interconnection complexity and parasitic effects while maintaining large-scale detection capability.
4Measurement precision
If computing resource intensive signal processing methods are used, then small signal processing capability improves, but system complexity and cost increase
Solution Approach 1:
The patent performs signal processing actions preliminary to further computation by implementing amplification, filtering, and correlation functions directly in the integrated circuit hardware. This preliminary processing reduces the computational burden on external processors by pre-enhancing signals and suppressing noise before data leaves the sensor array.
Solution Approach 2:
The patent replaces computing resource-intensive software-based signal processing with hardware-based integrated circuit processing. The signal processing functions are implemented through dedicated circuit elements fabricated on the same chip as the photodiodes, providing real-time processing with minimal computational resources required externally.
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 allows for the detection of optical signal levels below those processed by discrete circuits, reducing laser power needs, minimizing system size and power consumption, and enhancing signal processing efficiency with low production costs and reduced software complexity.
Implementation Method 1
Photodiodes have been used to convert optical signals (in the form of a photon flux) to an electrical signal in the form of a charge flux (current)
Data Source
AI summary
The system and method for multi-wavelength optical signal detection enables the detection of optical signal levels significantly below those processed at the discrete circuit level by the use of mixed-signal processing methods implemented with integrated circuit technologies. The present invention is configured to detect and process small signals, which enables the reduction of the optical power required to stimulate detection networks, and lowers the required laser power to make specific measurements. The present invention provides an adaptation of active pixel networks combined with mixed-signal processing methods to provide an integer representation of the received signal as an output. The present invention also provides multi-wavelength laser detection circuits for use in various systems, such as a differential absorption light detection and ranging system.