Non-interferometric measurement of Pancharatnam-Berry phase using stimulated second harmonic generation

We present a non-interferometric technique for measuring the geometric phase using stimulated second harmonic generation (S-SHG), addressing the limitations of interferometric methods. This approach exploits the phase sensitivity of S-SHG, which results from the coherent interaction between a stimulating seed and the second harmonic field driven by a common fundamental source. A controlled geometric phase is introduced via a QHQ wave plate sequence, and the S-SHG power is measured as a function of the relative phase between the interacting beams. The experimental results show excellent agreement with theoretical predictions based on Jones calculus and an independent interferometric measurement, confirming the validity of the proposed method. This interference-free technique provides a stable and precise alternative for geometric phase measurement, with potential applications in structured light, polarization optics, and quantum information processing.