Conical emission in β-barium borate under femtosecond pumping with phase matching angles away from second harmonic generation

摘要

The broadband parametric upconverted conical emission (CE) has been investigated in a β-barium borate crystal with phase matching angles away from second harmonic generation. A broad range of CE from 340 to 800 nm has been observed by varying the crystal thickness and the incident energy of the pump beam. It has been found that the tunability range can be increased with the thickness of the medium. The CE spectra and their angular positions have been measured and found to match with those calculated from recent theoretical models.