Abstract

Cylindrically polarized (CP) modes are promising laser beam modes for applications such as optical communication and optical trapping. While axisymmetrically polarized modes, whose symmetry is C_∞ with respect to the propagation axis have attracted much attention, the cylindrically polarized modes with higher-order-azimuthal indices l (higher-order CP modes) with the C_|l−1| symmetry are also important. For example, vector-vortex-modedivision multiplexing [1] needs many higher-order CP modes, tolerating only small local deviation in the symmetry of CP states. The higher-order Stokes parameters in the earlier study [2] are, however, not capable for describing CP modes with such local deviation. We have therefore introduced the extended Stokes parameters (ESPs) and the degree of polarization defined for the spatial distribution (DOP-SD; modified DOP) in the previous papers [3,4], which respectively give a quantitative description of the polarization states and the purity for any higher-order CP modes. In the present paper, we demonstrate the full quantitative analysis of l = 2 higher-order CP ultrashort pulses by using the ESPs and the DOP-SD in the whole spectral range (~770–~820 nm).

© 2015 IEEE