Ru Yang

Position Sensitive Silicon Photomultiplier With Intrinsic Continuous Cap Resistive Layer

A high-gain, position-sensitive photon number discriminating detector based on silicon photomultiplier (PS-SiPM) is proposed and fabricated. The device, compatible with standard CMOS fabrication process, is easy to implement owing to the intrinsic continuous and uniform cap resistive layer featured by an SiPM structure with bulk quenching resistor. Both the 2-D position information and the photon number of incident pulse light can be obtained from a tetralateral type configuration using a simple algebra calculation of its four readout signals. If one of the four anode electrodes on front side or the cathode electrode on rear side is used for signal output, the PS-SiPM can function as a regular SiPM with high resolved photon number discrimination. The device, with an active area of 2.2 mm × 2.2 mm, demonstrated spatial resolution of 78-97 μm, gain of 1.4 × 105 and 46-ps time jitter of transmission delay for multiple photons.

Time-Correlated Photon Counting (TCPC) technique based on a photon-number-resolving photodetector

In this report, we present Time-Correlated Photon Counting (TCPC) technique and its applications in time-correlated Raman spectroscopy. The main difference between TCPC and existing Time-Correlated Single Photon Counting (TCSPC) is that the TCPC employs a photon-number-resolving photodetector (SiPM, silicon photomultiplier) and measures exact photon number rather than counting single photon by reducing pulse light intensity, thus high measurement speed and efficiency can be expected. A home-made Raman spectrometer has demonstrated an Instrument Response Function (IRF) ~100ps (FWHM) based on TCPC with a strip SiPM (1mm×0.05mm, containing 500 micro cells), fast and weak Raman signals was separated from slow and strong fluorescence background of bulk trinitrotoluene（TNT）sample. The original Raman spectrum of bulk TNT, measured by TCPC technique, is compared with the result obtained by a commercial Micro-Raman Spectrometer.

Sub-100ps single photoelectron time resolution of a strip silicon photomultiplier for time-resolved optical spectroscopy

SiPM with epitaxial quenching resistors developed at NDL (Novel Device Laboratory, Beijing) could alleviate the conflict between large dynamic range and high photon detection efficiency (PDE). It can be used as low light level detector in various applications with excellent single photoelectron time resolution (SPTR) and photon counting capacity. SPTR is mainly determined by the intrinsic structure parameters of the SiPM. However, it is also limited to measurement setup, electronics readout and the ultra-small signal of single photoelectron level. In this work, we designed and fabricated a 1 mm × 1 mm strip SiPM array for possible applications in time-resolved optical spectroscopy. The SiPM array consists of sixteen 50 μm × 1 mm strip SiPM elements. Each element contains five hundred 6.5 μm × 6.5 μm micro avalanche photodiode (APD) cells with 10μm pitch. The strip SiPM demonstrated SPTR of 68 ps (FWHM), peak PDE of 17% around 450 nm and high photon number resolving and photon counting capability.

Effects of isolation trench depth on bulk integrated quenching resistors and breakdown voltage of the silicon photomultiplier with bulk integrated quenching resistors

Much attention has been paid to silicon photomultiplier (SiPM) for single photon resolution. The New Devices Laboratory, Beijing Normal University developed a SiPM with bulk integrated quenching resistors, which has simple, compact structure, can achieve high dynamic range. This paper presents a bulk resistor type SiPM with trenches isolation. The effects of the trench depth on quenching bulk resistors and breakdown voltage are studied by simulation. The bulk quenching resistors and breakdown voltage can be adjusted by the depth of the isolation trench when the wafer resistivity is high. The results are important for the design of the bulk resistors quenching SiPM.

One-dimensional single-photon position-sensitive silicon photomultiplier and its application in Raman spectroscopy

We present a one-dimensional (1-D) single-photon position-sensitive silicon photomultiplier (PS-SiPM) that can perform both photon number and position discriminations. The device, which features epitaxial quenching resistors and a continuous cap resistive layer for charge division, possesses two cathodes on top and one anode at the bottom. The PS-SiPM shows an active size of 2.2 mm × 2.2 mm and micro avalanche photodiode cell pitch of ~10 μm. The position measurement error (PME) and position resolution of the device are analyzed. The PME with low mean photoelectron number of approximately 0.11 is 29.6 ± 27.3 μm. The single-photon position resolution is 393.4 μm. When the photoelectron number increases from 1 to 7, the position resolution is improved from 393.4 μm to 56.2 μm. The application of the PS-SiPM in Raman spectroscopy for carbon tetrachloride (CCl4) at room temperature shows advantages of both CCD (rapid measurement) and photomultiplier tube (high gain, fast photon response, and simple readout electronics). This novel device concept exhibits potential as a low-cost and high-performance detector for various laser spectroscopies.