The first photon beam was successfully produced by laser Compton backscattering at the LEPS2 beamline, which was newly constructed at SPring-8 for the purpose to increase the beam intensity one order of magnitude more than that of the LEPS experiment
s and to achieve the large acceptance coverage with high resolution detectors. The BGOegg electromagnetic calorimeter with associated detectors are being set up at the LEPS2 experimental building for the physics programs, including the searches for $eta$-bound nuclei and highly excited baryon resonances. In parallel to the BGOegg experiments, the LEPS2 charged particle spectrometer will be prepared inside the 1 Tesla solenoidal magnet, transported from the BNL-E949 experiment.
Production of a GeV photon beam by laser backward-Compton scattering has been playing an important role as a tool for nuclear and particle physics experiments. Its production techniques are now established at electron storage rings, which are increas
ing worldwide. A typical photon intensity has reached $sim$ 10 $^6$ sec$^{-1}$. In the present article, the LEPS beamline facility at SPring-8 is mainly described with an overview of experimental applications, for the purpose to summarize the GeV photon beam production. Finally, possible future upgrades are discussed with new developments of laser injection.
