Multiwavelength spectral photon detection system with 10.9nm resolution capable of perform data stream at 420Gs/s

Abstract

Single Photon Detection (SPD) is the essential technology for the future of quantum cytometry and quantum biology. We have been developing SPD technology previously reported at DCS2022 but recently achieved detection and recording of photoelectron (PE) pulse width ⪅500ps with 1Gcps saturation count with near 7LOG Dynamic Range (DR). The current challenge involves developing a spectral photon detection system that works in the range from ultraviolet to near infrared region. We have developed a six-decade dynamic range spectrometer from 360nm to 820nm, with a 42 channels fiber array (42CH) that distributes each spectral window onto an individual pixel-coupled silicon photomultiplier (SiPM), each channel has a 10.9nm bandwidth. The detected PE streams of the 42CH are captured with an FPGA at 10Gs/s with 100ps time resolution using multi-GHz electronics and thermoelectric cooling, and produce a huge data stream of 420Gs/s. We have identified interference problems on the system which arise from using conventional packaging with gold wire connection in dry nitrogen such as oscillation, crosstalk between adjacent channels and interference from external radiation such as Wi-Fi and cellular RF signals. To resolve electrical interference and improve signal quality, the sensor chips were mounted on an eight-layer Chip-On-Board (COB). Improving the sensor environment was the other focus for our system. We have designed a two stagesthermoelectric device targeted at -30°C with a moisture getter in the sensor package to reduce the thermal electron and the dark count of the SiPM. This design is an innovative approach in the packaging method that helps to control the environment inside the sensor. Earlier photon spectroscopy required a considerable time to scan a full spectral range using a monochromator. Our newly developed 42CH multiwavelength spectrometer allows the capture of a spectral fingerprint in microseconds to microseconds with potential readout in SI units. The system under development will contribute various applications in the fast-developing quantum field.