MPPC Gain Control via Voltage Regulation and Histogram Analysis
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Solution Overview
Problem
Existing methods for controlling the gain of MPPC detectors, such as thermal control, are not suitable for use in all environments due to their temperature dependence and the simultaneous counting of thermal agitation electrons, which complicates the measurement of photon counts.
Innovation Solution
A method that acquires signals from an MPPC detector for predefined periods, forms an amplitude histogram, determines the positions of consecutive peaks, calculates an error signal based on peak deviations, and uses this signal to regulate the voltage applied to the detector, maintaining a predefined set point, thereby stabilizing the gain and zero of the detector independently of temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal control is used to control the gain of MPPC detector, then the gain can be stabilized, but the method cannot be used in all environments due to temperature dependence and thermal agitation electrons
Solution Approach 1:
The patent replaces the thermal control mechanism with an electrical control mechanism. Instead of using temperature to control gain, the invention uses voltage applied to the MPPC detector to control the gain. This substitution allows the detector to be controlled in environments where thermal control is not feasible, while still achieving stable gain through voltage regulation based on histogram peak analysis
Solution Approach 2:
The patent changes the control parameter from temperature to voltage. By applying voltage to the MPPC detector and analyzing the histogram of signal amplitudes, the system can control the gain without relying on temperature control. This parameter change enables operation in diverse environments while maintaining gain stability through electrical rather than thermal means
2Measurement precision
If MPPC detector operates in Geiger mode to detect photons, then photon detection capability is achieved, but thermal agitation electrons are simultaneously counted which complicates measurement
Solution Approach 1:
The patent implements a feedback mechanism where the histogram of signal amplitudes is continuously analyzed and the voltage is adjusted based on the measured peak positions. The system uses the ratio of peak positions as feedback to control the gain, automatically compensating for thermal agitation electrons by maintaining a predefined set point. This feedback loop distinguishes between photon signals and thermal noise through statistical analysis of the amplitude distribution
Solution Approach 2:
The patent converts the harmful effect of thermal agitation electrons into a useful feature. By analyzing the histogram of all signals (including thermal noise), the system uses the statistical distribution to determine the actual photon detection gain. The thermal electrons, rather than being mere noise, provide a reference distribution that helps calibrate and control the detector's response to actual photon events
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 precise control of the detector's sensitivity and zero measurement, enabling absolute photon counting regardless of temperature, and maintains stability across varying environmental conditions.
Implementation Method 1
an array of avalanche photodiodes operating in Geiger mode
Implementation Method 2
the simultaneous counting of the thermal agitation electrons
Data Source
AI summary
A method for controlling the gain and zero of a multiple pixel photon counter device, and light-measuring system implementing said method.Signals provided by the device are acquired for predefined periods, until a predefined total measurement time is reached, an amplitude histogram is formed from the acquired signals, the positions of two consecutive peaks, measurable on the histogram, are determined, an error signal is produced, which is equal to the deviation between both peaks and, by means of the same, the voltage supplying the device is regulated, so as to keep the deviation equal to a predefined set point.