How to Choose the Best Detector

Are you selecting the best sensor among avalanche photodiode, photomultiplier tubes? Silicon photomultipliers and photodiodes require assessing numerous sensor traits and the application’s requirement. This is not a simple task, but this guide will help you find the best detector. Some industrial, medical, and analytical apps require the detection of light.

Here is a Guide to Help You

Define the requirements of the application. Some of the parameters to consider include:

  • Level power level
  • Wavelength variety of incident light
  • Electrical bandwidth of the sensor amplifier
  • Mechanical prerequisites of the application like the size of the equipment, power usage of the equipment, and running temperature rate of the equipment


The moment the sensor area is narrowed based on the app, compute the signal-to-noise ratio under the conditions of the app. Plots such as signal-to-noise ratio and light power are ideal for comparing sensors.

Verify the computed outcome by measuring the signal to noise ratio in the application. Even though this process appears obvious, in practice, it’s always omitted. This leads to inappropriate sensor selection.

  • Generally, the PMT works best in a very low light level environment in UV to near-IR wavelength ranges. It’s ideally suitable for fluorescence spectroscopy like chemiluminescence, immunoassay for detecting NOx, and gamma cameras for medical imaging.
  • Essentially, the SiPM is between an APD and a PMT, it works best in applications that involve low light levels in the sunlight to visible wavelength ranges. Some of the examples include fluorescence measurement in applications like flow cytometry and DNA sequencing, and also scintillation measurement in higher energy physics experiments and positron emission tomography.
  • The APD works best in applications that entail low light levels and higher bandwidth applications performed in the near-IR. Some of the examples include laser rangefinding, particle counters, and barcode scanning.
  • The photodiode is suitable for applications that have lower-to moderate light levels in sunlight to the near-IR range. These applications comprise optical power meters, optical absorption measurement, and optical smoke sensors.

The ultimate test of a sensor unit is its signal-to-noise performance in a specific condition. It’s not the only test to which the detectors should undergo. For example, in specific IR applications, the APD might have the greatest S/N ratio, but its high-temperature coefficient might make it hard to use. So, the designer may prefer the greater stability of the photodiode irrespective of its lower signal-to-noise ratio.

What’s essential in determining the kind of sensor to use is choosing the perfect one for a specific application. You can go for avalanche photodiode or any other that suits your application. You should approach the choice of sensors with no bias and choose what works the best.