Fig. 1. Schematic of the generation of radially polarized and azimuthally polarized beams by a typical fiber CPA system. CFBG, chirped fiber Bragg grating; WDM, wavelength division multiplexer; ISO, isolator; AOM, acoustic-optical modulator; M1 and M2, reflective mirrors.

Fig. 2. (a) and (b) are the calculated intensity distribution for the formation of radial and azimuthal vector beams using linear superposition of orthogonally polarized HG modes. (c) and (d) are the measured intensity profiles by a CCD camera at maximum power.

Fig. 3. Laser performance at maximum output power. (a) The optical spectra of the Gaussian beam and radial and azimuthal vector beams. (b) The autocorrelation trace with sech² fit.

Fig. 4. Measured intensity profiles of the output vector beams after passing through a rotated linear polarizer at different output powers. (a) The radially polarized vector beam, with (b) the average output power. (c) The azimuthally polarized vector beam, with (d) the average output power. The white arrows exhibit the transmission axis of the polarizer.

Fig. 5. Relationship between incident Gaussian beam power and vector beam power. The dot lines are the linear fitting curves. The insert picture is the intensity profiles of Gaussian beams captured by a CCD camera at maximum output power.