An optical assembly to generate the second and third harmonic

Abstract

Optical assembly for generating the second and third harmonic frequencies of a laser beam using two optically nonlinear crystals (C1 and C2) placed in a temperature-controlled environment. The first optically nonlinear crystal (C1) converts the fundamental harmonic frequency to the second harmonic, while the second optically nonlinear crystal (C2) converts the fundamental and second harmonics to the third harmonic. The system includes beam intensity attenuation mechanisms using a first half-wave plate (HWP1) and first and second polarizers (P1, P2) that direct the beam according to the user's requirements. Motorized linear shifts (T1, T2) provide switching between harmonic frequency generation modes. Different cuts of the optically nonlinear crystals (C1 and C2) allow for optimization of phase matching and conversion efficiency. This assembly is designed for highly accurate and flexible generation of harmonic laser beams with wide industrial applications, especially in laser micromachining.