Photomultiplier (CPM)
(19mm Types)

Customized Photomultiplier (CPM) – Types

The Customized Photomultiplier (CPM, formerly Channel Photomultiplier) is actually an ultra-high sensitive, advanced monolithic version of the traditional glass photomultiplier tube (PMT). It may replace conventional PMTs or Avalanche Diodes. Although CPMs operate on basically the same principles as PMTs, they have several advantages: they generate significantly less dark current, are less influenced by external magnetic fields, are equipped with an internal electronic shutter and are more rugged and less breakable.

They enable to detect the lowest light levels (single photons) occurring in nature. The CPM consists of a photocathode evaporated on an entrance window, which is mounted under high vacuum to a small bended glass tube (channel) with an anode at the end. Once a photon has passed the entrance window and hit the cathode, a photoelectron is emitted into the vacuum. By a high voltage difference between the cathode and the anode (up to 3000 volts), the photoelectron is accelerated towards the anode. On its way to the anode, the electron has to pass the channel and due to the special shape, it hits the semi-conductive surface of the channel several times. Every time this happens, further electrons are emitted by the process of secondary emission. Finally, at the anode, up to 1E8 electrons can be read out, generated by only one electron at the cathode.



  • Extremely low background noise
  • Best low light level detection limits
  • High dynamic range & gain
  • Low microphonic & magnetic sensitivity
  • Compact size & rugged design
  • Multiple photocathode and window selections
  • Plug and play for shortest design-in and time-to-market
  • Customizations and added features available



  • Photon Counting
  • Luminescence & Fluorescence Spectroscopy
  • Microplate Readers
  • Clinical Diagnostics
  • DNA & Cell Analysis
  • Particle Measurements
  • Optical Emission Spectroscopy
  • Industrial SpectroscopyNucleic
  • Acid Amplification (PCR)
  • Hygiene Monitoring
  • Sulfur Analysis

Configuration parameters


  • Wavelength of interest: 115nm to 900 nm
  • Active diameter: 5mm, 15mm, (9mm upon request)
  • Input windows: MgF2, Quartz, UV-Glass, Borosilicate Glass
  • Photocathodes: CsTe, CSI, Bialkali, Low Noise Bialkali, Yellow Enhanced, Multialkali (S20),
  • Multialkali Red Enhanced (S25)
  • PhotonCounting Type



Besides the standard configuration we do also take into account application-specific requirements. Thus we invite our customers to provide such information. Confidentiality is of course guaranteed.