An alpha emitter (241Am) deposited externally as a thin source on a small NaI(Tl) crystal has been employed as a miniature light pulser. Applications include photomultiplier tube calibration and stabilization, and high precision light collection efficiency mappings for design optimization of scintillation and Cˇerenkov detectors. Improved resolution has been reported by Menefee and Cho [IEEE Trans. Nucl. Sci.NS‐13,No. 3, 159 (1966)] for NaI(Tl) crystals doped internally with241Am.