LP_mode_value

ofiber.cylinder_step.LP_mode_value(V, ell, em)[source]

Calculate guided b for mode (ell,em) in a circular step-index fiber.

b is the normalized propagation constant. Each guided mode in an optical fiber has a specific value of b that depends on the fiber parameter V and the mode number.

If no mode exists, a value of None is returned

The LP_lm is specified by the (ell,em) to avoid confusion between the number 1 and the letter l.

For cylindrical fibers, em is a positive integer: thus there are modes LP_01, LP_02, but not LP_10.

Parameters:

  • V – V-parameter for optical fiber [-]

  • ell – primary fiber mode (integer) [-]

  • em – secondary fiber mode (integer>0) [-]

Returns:

guided normalized propagation constant for mode (ell,em) [-]