The Structure and Composition of Photon Counters

1、 Introduction



Briefly introduce the importance and application of photon counters in the field of optics.

Explain the basic principles and classifications of photon counters, including basic types, background compensation types, and radiation source compensation types.

2、 The basic structure of photon counters

Photomultiplier tube

The working principle of a photomultiplier tube: The photocathode receives radiation from light, generates photoelectrons, and through the doubling effect of the doubling electrode, forms an electrical pulse signal.

Types of photomultiplier tubes: Introduce different types of photomultiplier tubes, such as linear focusing type, microchannel plate type (MCP), louver type, box grid type, metal channel type, and fine mesh type, as well as their characteristics and applications.


amplifier

The function of an amplifier is to amplify the weak electrical pulse signal output by the photomultiplier tube to a sufficient amplitude for subsequent processing.

Requirements for amplifiers: Sufficient bandwidth, fast rise and fall times, good linearity, and gain stability are required.

Discriminator

The function of the discriminator is to selectively eliminate noise pulses and interference signals by setting the first discriminator level V1 and the second discriminator level V2 through a single photon pulse signal.
The working mode of the discriminator is window type, which controls the range of pulse passage by setting the value of V.

Counter

The function of a counter is to record the number of pulse signals passing through the discriminator, i.e. the number of photons.

Counter requirements: have a high counting rate and counting capacity.

3、 Power supply circuit and signal output of photon counter

Power supply circuit

The requirements for the power supply voltage of photomultiplier tubes: usually in the order of kilovolts, a certain inter electrode voltage needs to be distributed between the cathode, focusing electrode, multiplier electrode, and anode.

Guarantee of voltage stability: Resistance voltage dividers or Zener diodes are used to ensure voltage stability.

signal output 

Load resistance output: The current signal is converted into a voltage signal output through the load resistance.

Operational amplifier output: Use an operational amplifier to further amplify and process the signal before outputting.

4、 The structure and working principle of a mixed pixel photon counter

Basic structure

Sensor layer and readout chip: Introduce the basic components of a hybrid pixel photon counter, including a pixelated sensor layer and readout chip.

Pixelization structure: Each pixel corresponds to a detector and a processing unit, achieving photon counting and other measurement functions.



working principle

Photon detection and signal processing: Photons hit the sensor to generate electron hole pairs, which are amplified, compared, and counted to achieve photon counting.

There are three working modes: counting mode, TOT mode, and TOA mode, which are suitable for different measurement needs.

5、 The Application of Photon Counters

Environmental monitoring and air quality assessment

The application of optical particle counter in measuring the concentration of airborne particulate matter.

industrial process control 

The optical detection application of photon counters in industrial production lines.

Research field

In research in fields such as photonics and quantum optics, photon counters are an important experimental tool.

6、 Conclusion

Summarize the structure and composition characteristics of photon counters.

Looking forward to the future development trends and application prospects of photon counters.

When writing a complete article, you can expand and deepen it based on the above framework, adding specific experimental data, charts, and case analysis to make the article more substantial and vivid. At the same time, pay attention to maintaining the logic and organization of the article to ensure that readers can clearly understand the structure and composition of the photon counter.