Jun 3 – 5, 2022
Parador El Saler, Valencia, Spain
Europe/Zurich timezone

Monolithic integration of metalens array in multipixel photon counter for enhanced photodetection efficiency

Jun 5, 2022, 8:45 AM
Parador El Saler, Valencia, Spain

Parador El Saler, Valencia, Spain


Dr Ryosuke Ota (Hamamatsu Photonics K.K.)


Silicon photomultiplier (SiPM) consisting of single photon avalanche diode (SPAD) array has been widely used in many types of applications, those requires photon counting capability. Dynamic range of SiPM, which is one of the representative characteristics, is generally limited by the number of SPADs composing the SiPM. Its dynamic range can be expanded by using small size SPAD, e.g., 10, 15, 25 um, and increasing the number of the SPADs, however, small size SPADs cannot keep high geometric fill factor (FF) basically due to existence of the trench, resulting in low photodetection efficiency (PDE). Although using microlens array on top of the SiPM surface has been proposed to avoid the degradation of the effective FF, microlens is not suitable for scintillation-based applications in terms of transparency, packaging, and coupling. Here, we propose the use of metalens array instead of the microlens array to overcome the problems abovementioned and investigate its applicability using multipixel photon counter (MPPC). Metalens array geometrically corresponding to SPAD array was directly fabricated and monolithically integrated in the MPPC. The metalens array correctly guides incoming photons to the center of the SPAD, where the relative photodetection efficiency is the highest. Thus, the metalens-integrated MPPC showed the enhanced FF, in other words, the enhanced PDE. Furthermore, we show, as a metric of scintillation-based applications, an improved coincidence time resolution using the metalens-integrated MPPC. Finally, we discuss our future strategies of the use of metalens.

Primary author

Dr Ryosuke Ota (Hamamatsu Photonics K.K.)


Mr Soh Uenoyama (Hamamatsu Photonics K.K.)

Presentation materials