comnum.lambertian_mode

comnum.lambertian_mode(semi_angle_rad)

The Lambertian mode n = -ln 2 / ln cos Φ½ of a source of semi-angle at half power Φ½ (rad): 1 for 60°, 0.65 for 70°.

Parameters:

semi_angle_rad (float) – the semi-angle at half power, in (0, π/2).

Returns:

the mode.

Return type:

float

Raises:

ValueError – for an invalid parameter (the message names it).