Abstract :
We model the spectral beam combining of a fiber laser array in the external resonator configuration, as proposed by V. Daneu et al. A diffraction integral-based approach is used that leads to design principles for most significant measures of performance, such as efficiency, bandwidth, and beam quality. Sensitivity to alignment and positioning errors is also characterized. Off-axis transform lens aberrations are shown to limit array size, and two design criteria are applied to compare the performance of simple spherical, compound, and aspheric lenses. The results indicate that a simple aspheric lens is superior in meeting the proposed criteria to a well-designed compound (quadruplet) lens with spherical surfaces. Application to the efficient coupling of a laser array to a multimode fiber core is discussed as a final example
Keywords :
aberrations; aspherical optics; fibre lasers; laser arrays; laser beams; laser cavity resonators; lenses; measurement errors; optical design techniques; alignment sensitivity; array size; aspheric lenses; bandwidth; beam quality; compound lenses; design criteria; design principles; diffraction integral-based approach; efficiency; external resonator configuration; fiber laser array; fiber lasers; laser array; multimode fiber core; off-axis transform lens aberrations; positioning errors; quadruplet lens; spectral beam combining; spherical lenses; Bandwidth; Diffraction; Fiber lasers; Laser beams; Laser modes; Laser theory; Lenses; Optical arrays; Optical design; Optical fiber theory;
