spatial_focal_curve#
- esis.optics.poletto.spatial_focal_curve(alpha, beta, entrance_arm_radius, grating_sagittal_radius)#
Equation 34 of Thomas and Poletto (2003) :param alpha: Nominal incidence angle of the beam on the grating. :param beta: Nominal diffraction angle of the beam off the grating. :param entrance_arm_radius: Distance from the center of then grating to the center of the source. :param grating_sagittal_radius: Sagittal radius of the diffraction grating :return: The length of the exit arm for optimal spatial focus