A new theoretical study shows that abruptly removing a mirror during photon reflection creates multiple photons across a range of frequencies.
Three Norwegian physicists have calculated the outcome of yanking away a mirror while a single photon reflects from it. The sudden change turns the original narrowband photon into a superposition that includes many photons at different frequencies.
The work appears in Physical Review Letters with DOI 10.1103/94pm-hp34. It builds on the idea that a photon is an extended object in time and frequency rather than a point particle.
Performing the experiment would require single-photon sources with narrow bandwidth and materials that switch from reflective to transmissive in roughly 10 femtoseconds. The researchers note that similar mirror-switching techniques already shorten ultrashort laser pulses, but single-photon versions remain to be demonstrated.
They estimate that suitable experiments could become feasible within about a year.