Probing the semi-macroscopic vacuum by higher-harmonic generation under focused intense laser fields

Understand

The invention of the laser immediately enabled the detection of nonlinear photon-matter interactions, as manifested for example by Franken et al.'s detection of second-harmonic generation.

• With the recent advancement in high-power, high-energy lasers and the examples of nonlinearity studies of the laser-matter interaction by virtue of properly arranging lasers and detectors, we envision the possibility of probing nonlinearities of the photon interaction in vacuum over substantial space-time scales, compared to the microscopic scale provided by high-energy accelerators.
• Specifically, we introduce the photon-photon interaction in a quasi-parallel colliding system and the detection of higher harmonics in that system.
• The method proposed should realize a far greater sensitivity of probing possible low-mass and weakly coupling fields that have been postulated.