Quantification of Einstein's concept of the photon experimentally confirmed by the photo-electric effect

Einstein explained the experimental characteristics of the photo-electric effect by the concept that the photon is a localized packet of electromagnetic radiation with the mechanism: photon + atom → emitted electron. A classical plane wave theory of light concluding that the photoelectric effect can be explained without localized photons is reexamined and found to have been flawed in predicting no time delay for photoelectron emission; this accords with Millikan's conclusion (based upon energy conservation) that a classical plane wave would entail a delay prior to emission of the order of hours. The quantification of Einstein's localized packet concept as a solitary wave one wavelength in length (one period long in time) predicts a delay of one period of the photon's oscillating field, which accords with the experimentally measured response time being a few femtoseconds.