Strong double space-time wave packets using optical parametric amplification
Zhaoyang Li, Yuxin Leng, Ruxin Li
Abstract The space-time (ST) wave packet, a new type light source with many new features, has already found applications in weak-field optics, however its generation method limits its energy and therefore its application in strong-field optics. We report that the type-I collinear optical parametric amplification (OPA) is a natural amplifier for ST wave packets, because in it, the ST spectrum (i.e., angle-dependent phase-matching spectrum) of the signal and idler has the same analytical expression as that of ST wave packets under the narrowband approximation. The high gain in a thin-crystal OPA allows for large energy amplification while ensuring unchanged ST correlation. Meanwhile, for the first time, a double ST wave packet containing two collinear-propagating ones of the amplified signal and the generated idler via the nondegenerate OPA is reported, which with short- and long-wavelengths (relative to the degenerate-wavelength) have superluminal and subluminal velocities, respectively. This study realizes energy amplification, wavelength conversion, and velocity switching of ST wave packets and will certainly expand the application in many fields.
Communications Physics•Nov 21, 2022•6 citations