Silicon Photomultiplier (SiPM)

Various applications require optical sensors with extremely high sensitivity in order to detect weak light down to the single photon. If the spatial resolution does not have the highest priority, silicon photomultipliers (SiPM) optimally meet this requirement. Silicon photomultipliers are extremely sensitive optical detectors for the measurement of the smallest amounts of light and for the detection of single photons. They are used in various applications and are ideally suited for medical diagnostics or in high-energy physics, they are indispensable for the detection of single particles.

One interesting area is high-energy physics in which the detection of individual particles is indispensable. Another widespread application field of Silicon photomultipliers is in nuclear medicine in the field of positron emission tomography (PET). Here, a radioactive substance is supplied to the body as a marker (tracer) for metabolic activity. With the decay of the substance positrons (positively loaded elementary particles) are formed that destroy themselves in combination with the electrons as their counterparts and release energy in the form of photons. During this process two photons with 180° difference in impulse direction form. These opposite propagating photons hit inside a tube and, by their arrival time, provide information about the place of origin, or positron emission. The differences of the decay rate in the body are of particular interest, because the chosen substances accumulate, for example, on tumor cells, marking areas with high intensities suspected tumor areas.

Analog Silicon Photomultiplier of Fraunhofer IMS in housing
© Fraunhofer IMS
Analog Silicon Photomultiplier of Fraunhofer IMS in housing

SiPMs are based on the SPAD technology and take advantage of the extreme sensitivity and speed of the SPAD diodes. Fraunhofer IMS has the experience and the competence to develop and produce cost-effective Silicon Photomultipliers with SPADs integrated into CMOS technology (CSPADs). The design can be tailor-made and the individual requirements of the customers can be realized. This includes both analog SiPMs that deliver the photon rate in from of an output voltage and digital SiPMs that count individual photons and an additional time stamp can be read out from the chip binarily.


CSPAD detectors combine highly dynamic three-dimensional imaging with reliable algorithms for high-performance operation even in changing weather conditions.

CMOS SPADS for LiDAR Applications

SPADs from Fraunhofer IMS are characterized by a low dark count rate and a high dynamic range.

TOF Image Sensors

Fraunhofer IMS develops special high-resolution sensors for indirect time-of-flight applications.

Our technologies - Innovations for your products

Single Photon Avalanche Diode (SPAD)

With single-photon avalanche diodes, direct time-of-flight (ToF) measurements for distance calculation are possible.

CMOS Charge Coupled Devices (CCDs)

Fraunhofer IMS develops customized CMOS-CCD structures and sensors with extremely high dynamic range for TDI applications.

Backside Illuminated Sensors (BSI)

Fraunhofer IMS develops and uses processes and latest bonding technologies on chip and wafer level for the fabrication of backside illuminated optical sensors.

Highly sensitive image sensors

Fraunhofer IMS realizes further special photosensitive devices like pinned photodiode, high resolution sensors for indirect time-of-flight and line sensors with high sensitivity.

Our technology areas - Our technologies for your development

MEMS Technologies

Low temperature processes for post-CMOS integration of MEMS sensors or actuators.


Biofunctional Sensors

Tools for medical diagnostics.

Specialized technologies

The Fraunhofer IMS also offers special technologies e.g. high-temperature technology.


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