SiPM PDE Measurement

Using a white light source did not work for determining the PDE of the SiPM. To prevent detector saturation, the power of the light source needs to be constant throughout the range scanned otherwise the SiPM will be either saturated in some regions and errors in other regions will be incredibly large (see Figure below). A good LED/lamp power has been observed to be about 75E-12 W. Instead of using a white light source, LEDs will be used to sample the SiPM quantum efficiency at several points in the visible spectrum.