def load_fiber_parameters(self, pulse_in, fiber, output_power, z=0):
        """
        This funciton loads the fiber parameters into class variables.
        """
        self.betas[:]  =  fiber.get_betas(pulse_in, z=z)
        # self.alpha[:]  = -fiber.get_gain(pulse_in, output_power) # currently alpha cannot change with z
        self.gamma     =  fiber.get_gamma(z=z)