Detection of a new SRS‐promoting phonon mode and cross‐cascaded χ(3)‐nonlinear lasing in single crystals of calcite (trigonal CaCO3)

Abstract

AbstractFor calcite (CaCO3), one of the pioneer crystals in nonlinear optics, new results of stimulated Raman scattering (SRS) spectroscopy are presented. Among them are the discovery of a new SRS‐promoting vibration mode with ωSRS2 ≈︁ 282 cm‐1 and its participation, together with the main SRS mode ωSRS1 ≈︁ 1086.5 cm‐1, in cross‐cascaded (χ(3) ↔ χ(3)) nonlinear‐lasing generation, as well as the observation of efficient self‐upconversion via cascaded parametric four‐wave processes of one‐micron Stokes and anti‐Stokes χ(3)‐lasing into the UV‐region of third harmonic generation. The investigations show that calcite is able to generate a χ(3)‐lasing comb of more than two octaves bandwidth. The article also gives a brief review on the discovery and study of the SRS‐effect in natural crystals (minerals), which have expanded our ability to study the photon‐phonon nonlinear‐laser interactions in crystalline materials. A short summary of information about χ(3)‐lasing properties of the triangular planar structure units in SRS‐active crystals is included.