rraman.getHomogeneousDamping¶

rraman.getHomogeneousDamping(t, Gamma, alpha=0, lmbda=0)¶

Calculates the damping term arising from the homogeneous linewidth of the electronic transition. Offers phenomenological support for Stokes shift.

Note

Added phenomenological Stokes shift to input parameters on 10-12-2015. See for example New J Phys 11, 015001 (2009), Eqs. (1) and (2).

Parameters:

t (array) – Time axis (fs).
Gamma (float) – Decay rate according to $1 / \tau$ in (cm-1), where $tau$ is exponential dephasing time.
alpha (float) –
Line shape parameter:
- 1 = Gaussian
- 0 = Lorentzian
lmbda (float) – Phenomenological Stokes shift (cm-1) which is added as imaginary part to g(t). Compared to the Brownian oscillator models, lmbda is the observed Stokes shift. (default = 0)

Returns:

Damping term in the time domain, $e^{-g(t) - i \lambda t / 2 \hbar}$ .