The upper limit of the laser field strength in a perfect vacuum is usually considered as the Schwinger field,corresponding to∼1029 W/cm2.We investigate such limitations under realistic nonideal vacuum conditions and find that intensity suppress
Over the past decades,photonics has transformed many areas in both fundamental research and practical applications.In particular,we can manipulate light in a desired and prescribed manner by rationally designed subwavelength structures.However,constructin