First Sensor has extended its range of optical sensors with solid-state silicon photomultipliers (SiPMs) for the detection of ultra-low light levels down to single photons. Compared to conventional photomultiplier tubes, SiPMs offer low operating voltage, temperature stability, immunity to magnetic fields and a much smaller size for easy system integration. The detectors are optimised for near ultraviolet (Series SiPM-NUV) or red, green and blue (Series SiPM-RGB) light detection with peak sensitivities at 420nm or 550nm.
The silicon photomultipliers consist of a matrix of multiple avalanche photodiode (APD) micro-cells operated above their breakdown voltage (Geiger mode). NUV- and RGB-SiPMs from First Sensor feature extremely low temperature coefficients of the breakdown voltage and gain, which allows for highly accurate and stable measurements. Enhanced materials and semiconductor technology enable low-noise devices with reduced dark count rate, crosstalk and very low afterpulsing probability typ. <4 per cent.
The precision SiPM detectors are designed to achieve very high gain (>106) and high photon detection efficiencies. The edgeless SiPM dies ensure high cell fill-factors and maximised active areas in array arrangements. The Chip-Scale-Package (CSP) provides a cost-effective and RoHS-compliant solution suitable for reflow soldering. For custom specific applications, First Sensor develops and manufactures arrays, modules and complete systems for OEM customers worldwide.
Typical applications of silicon photomultipliers from First Sensor include high energy physics, medical diagnostics, nuclear medicine, homeland security and analytical instruments. Due to the immunity to external magnetic fields, SiPM detctors are ideal for medical imaging applications such as combined tomography systems using magnetic resonance tomography (MRT) and positron emission tomography (PET) or single photon emission computed tomography (SPECT).