Fig. 2: The far-field characteristics of perovskite bullseye VCSELs.

a The beam profiles of bullseye VCSEL recorded in the forward direction and backward direction. The white dashed circles represent 10° and 20° as an angular scale bar. b The polarization state of the donut shaped laser beam after a linear polarizer. c, d The self-interference patterns of the forward and backward donut, respectively. The white dashed circle corresponds to the angle of 4 degree. Here the pump fluence is 20.5 μJ/cm2.