We report a photonic memory operation of an exciton absorptive reflection switch, consisting of a multiple quantum well modulator, a distributed Bragg reflector (DBR), and a heterojunction phototransistor (HPT). For the memory function, some of the bias light incident on the modulator passes through the DBR to illuminate the HPT. The state of the device is maintained after removing the input light incident on the phototransistor and is reset by removing the bias light incident on the modulator. Waveform reshaping and retiming of the disordered input pulse is also demonstrated.