Clarification Requested

If “empty space” is completely devoid of “ all the matter and radiation”, and then you blast the tiny region of “empty space” with extremely powerful photon radiation generated by the laser method, it would seem that you are depositing a very large amount of radiation into the tiny region of “empty space”. So the resulting “empty space” + radiation would appear to violate your definition of “empty space”.

Could the successful production of electron/positron pairs be more simply interpreted via E=mc², without needing any assumptions about speculative “vacuum fluctuations”?

Can anyone clarify this?

Eric Weinstein On The State Of Theoretical Physics