fiber.brillouin_gain_spectrum

brillouin_gain_spectrum(
    detuning: float | numpy.ndarray,
    *,
    brillouin_linewidth: Annotated[
        float, exclusiveMinimum=0, units='Hz'
    ] = 20000000.0,
) -> numpy.ndarray | float

Normalised Brillouin gain, a Lorentzian centred on the Stokes shift.

$$g(\nu) = \frac{(\Delta\nu_B/2)^2} {(\nu - \nu_B)^2 + (\Delta\nu_B/2)^2}$$

Args

• detuning: Offset from the Brillouin shift, in Hz.
• brillouin_linewidth: Full width at half maximum, in Hz.

Returns

Gain normalised to 1 at line centre.