Regular Article

Intrinsic resonant enhancement of light by nonlinear vacuum

Institute of Laser Engineering, Osaka University, 2-6 Yamada-Oka, Suita, Osaka 565-0871, Japan

^a e-mail: shibata-ka@ile.osaka-u.ac.jp

Received: 30 July 2020
Received in final form: 17 September 2020
Accepted: 23 September 2020
Published online: 15 October 2020

Abstract

In nonlinear electromagnetism in vacuum, a classical electromagnetic wave itself can generate another wave. A classical field can become a source for a nonlinear correction via the polarization and magnetization of vacuum. We elucidate that a resonant generation is intrinsic to the theoretical structure of nonlinear electromagnetism. The resonance can take place when the phases, or the cycles of the source and the nonlinear correction match. We demonstrate two specific systems as examples. For a plane wave and constant fields, nonlinear corrective electromagnetic fields are resonantly enhanced with distance. It is shown in a stationary special solution. For more realistic system, we have considered the case of a standing wave in a cavity with an appropriate initial and boundary conditions. As a result, the corrections are resonantly enhanced with time. The resonance effect in the cavity is shown to be observed more effectively by combining a static magnetic flux density. We have evaluated the resonant effect using concrete parameters of current experiments. The demonstrated resonance can be combined with existing proposals to enable experimental detection of nonlinear optical effects of vacuum easier.