Degree of paraxiality of coherent and partially coherent Airy beams

According to the definition of the degree of paraxiality for a monochromatic light beam, analytical expressions for the degree of paraxiality of coherent and partially coherent Airy beams are derived. Numerical results show that the degree of paraxiality of coherent and partially coherent Airy beams is determined not only by the characteristic length of the incident beam, but also by the exponentially truncation factor of the beam. The degree of paraxiality is also dependent on the initial coherence length of Airy beam. Our results are helpful to determine an Airy beam be paraxial or nonparaxial.

► Analytical expressions for the degree of paraxiality of a coherent and partially coherent Airy beam are derived.
► Degree of paraxiality of a coherent Airy beam is determined by beam’s characteristic length and exponential truncation factor.
► Degree of paraxiality of a partially coherent Airy beam is decreasing as coherence length is decreasing.