Recent topics of particle identification and photodetection

The paper reviews recent progress in particle identification and photodetection. The main emphasis is on ring imaging Cherenkov detectors using aerogel and quartz radiators, and associated photodetectors in the visible light region, which have been developed in the past several years for the present and future B physics programs. It is shown that detection of a Cherenkov photon with precise time resolution at an order of 10 ps has become one of recent trends to improve particle identification performance.