NON-COLLINEARLY PHASE-MATCHED FREQUENCY MIXING

• Main Authors: SCHÜTTLER, Jens, HAGEMANN, Christian
• Format: Patent
• Language: English
• Published: 02.05.2024
• Subjects: BASIC ELECTRIC ELEMENTS; DEVICES USING STIMULATED EMISSION; ELECTRICITY

A laser apparatus with non-collinearly phase-matched frequency mixing includes a nonlinear crystal generating an output laser beam from non-collinearly phase-matched frequency mixing of first and second input laser beams. The output laser beam is subject to walk-off in a walk-off plane. The second input laser beam is less powerful than the first input laser beam. The first input laser beam is directed to more closely align its Poynting vector to the output beam Poynting vector than in collinear phase matching. To achieve good spatial overlap in this phase matching scheme, the second input laser beam is elongated in the walk-off plane, such that the second input laser beam has a greater transverse size than the first input laser beam in the walk-off plane. This non-collinear phase matching scheme is capable of achieving an improved beam quality of the output beam, as compared to collinear phase matching with circular input beams.