This work is aimed at a novel program method that is assisted by light for capacitorless 1T-DRAM based on parasitic bipolar junction transistor operation. Experimental results clearly show that a flash of light triggers a distinctive binary memory state in the capacitorless 1T-DRAM. During the operation of the 1T-DRAM, the gate voltage is sustained at a negative, constant value. The sensing margin is 54 mu A and the hold state corresponding to the data retention time is retained over a few seconds. The proposed program method can therefore be considered as a promising candidate for future DRAM applications based on an optical interconnection system.