The Large High Altitude Air Shower Observatory (LHAASO), situated on Haizi Mountain in
Daocheng County, Sichuan Province, at an average altitude of 4, 410 meters, is home to the Wide
Field-of-view Cherenkov Telescope Array (WFCTA), a critical component of which is the laser
calibration systems (LCS). The energy measurement systems within the LCS are responsible for
accurately measuring the energy of laser beams emitted to the field of view of WFCTA, and are
comprised of an energy sensor, energy meter, and temperature control system. This paper presents
the results of the relative calibration and performance testing of the energy sensor, which serve as
the foundation for the normal operation of the LCS.