Numerical Investigation of Effect of Beam Waist in the Presence of One Dimension Diffraction Effect in Second Harmonic Generation

In this paper, we have analyzed the effects of beam waist (omega 0) on second harmonic generation (SHG) in the presence of 1-dimension diffraction effect at phase-matching condition. The fundamental wave is modelled as a Gaussian beam and depletion, incident with beam waist at the entrance plane of the nonlinear crystal to generate second harmonic waves. Specifically, we simulate the SHG intensity profile using a Gaussian fundamental beam, converting 1560 nm laser light to 780 nm, having length 20 mm with an effective nonlinear coefficient of 3 pm/V. The simulation results (in 3-Dimension) reveal a significant increase in SHG conversion efficiency as the beam waist increases from 50 & micro;m to 120 & micro;m for short normalize crystal lengths. However, at longer normalize crystal lengths, the efficiency decreases due to the effects of diffraction, highlighting the critical balance between incidence beam and diffraction in optimizing SHG performance.