What is the difference between MPPC and APD?

The gain of MPPC is as high as about 106, while that of APD is several ten to hundred times.The bias voltage needed for MPPC is as low as about 70 V, while that for APD is about 200 to 300 V.

Noise signals are superimposed on the output. What should I do?

Check the following points:
・ Check if power supply is correctly connected.
・ Check if background light is incident on the MPPC.
MPPC is a photon counting device capable of detecting even very weak background light. It is recommended to use the MPPC in a dark environment as much as possible, where background light other than signal light is not incident on the MPPC. Also, do not use a switching power supply but use a series power supply with low ripple noise. If no improvement is seen, contact our sales office.