  We report the test of many of the key elements of the laser-based calibration
system for muon g - 2 experiment E989 at Fermilab. The test was performed at
the Laboratori Nazionali di Frascati's Beam Test Facility using a 450 MeV
electron beam impinging on a small subset of the final g - 2 lead-fluoride
crystal calorimeter system. The calibration system was configured as planned
for the E989 experiment and uses the same type of laser and most of the final
optical elements. We show results regarding the calorimeter's response
calibration, the maximum equivalent electron energy which can be provided by
the laser and the stability of the calibration system components.
