Figure 3
From: The Double Jones Birefringence in Magneto-electric Medium
The region z > 0 is vacuum and the region z < 0 is magneto-electric medium.
θin is the incident angle for k0. The parallel and perpendicular components are k‖ and k^ respectively. The range of θin is constrained by β and for 
surface wave along the plane z = 0 is shown.
