Raman.jl

(R::AbstractRamanResponse)(t, ρ)

Get the full response function at time t and density ̢ρ.

RamanRespIntermediateBroadening(ωi, Ai, Γi, γi, scale)

Construct an intermediate broadened model with component positions ωi [rad/s], amplitudes Ai, Gaussian widths Γi [rad/s] and Lorentzian widths γi [rad/s]. The overall response is scaled by scale. Based on Hollenbeck and Cantrell, "Multiple-vibrational-mode model for fiber-optic Raman gain spectrum and response function", J. Opt. Soc. Am. B/Vol. 19, No. 12/December 2002.

RamanRespRotationalNonRigid(B, Δα, τ2, qJodd, qJeven;
                            D=0.0, minJ=0, maxJ=50, temp=roomtemp,
                            τ2=nothing, Bρ=nothing, Aρ=nothing)

Construct a rotational nonrigid rotor Raman model.

Arguments

• B::Real: the rotational constant [1/m]
• Δα::Real: molecular polarizability anisotropy [m^3]
• qJodd::Integer: nuclear spin parameter for odd J
• qJeven::Integer: nuclear spin parameter for even J
• D::Real=0.0: centrifugal constant [1/m]
• minJ::Integer=0: J value to start at
• maxJ::Integer=50: J value to sum until
• temp::Real=roomtemp: temperature
• τ2::Real=nothing: coherence time [s]
• Bρ::Real=nothing : density dependent broadening coefficient [Hz/amagat]
• Aρ::Real=nothing : self diffusion coefficient [Hz amagat]

Only one of τ2 or Bρ should be specified. If Bρ is specified then Aρ must be too.

References

• Full model description: Laser & Photonics Reviews, 16, p. 2100426, (2022) doi: 10.1002/lpor.202100426.
• We followed closely: Phys. Rev. A, vol. 92, no. 6, p. 063828, Dec. 2015, But note that that paper uses weird units, and we converted it to SI for the above reference.

RamanRespNormedSingleDampedOscillator(K, Ω, τ2)

Construct a simple normalised single damped oscillator model with scale factor K, angular frequency Ω and density independent coherence time τ2.

The scale factor K is applied after normalising the integral of the response function to unity.

RamanRespVibrational(Ωv, dαdQ, μ; τ2=nothing, Bρ=nothing, Aρ=nothing)

Construct a molecular vibrational Raman model (single damped oscillator).

Arguments

• Ωv::Real: vibrational frequency [rad/s]
• dαdQ::Real: isotropic averaged polarizability derivative [m^2]
• μ::Real: reduced molecular mass [kg]
• τ2::Real=nothing: coherence time [s]
• Bρ::Real=nothing : density dependent broadening coefficient [Hz/amagat]
• Aρ::Real=nothing : self diffusion coefficient [Hz amagat]
• C::Real=0 : constant linewidth [Hz]

Only one of τ2 or Bρ should be specified. If Bρ is specified then Aρ must be too.

References

• Full model description: S-.F. Gao, Y-Y. Wang, F. Belli, C. Brahms, P. Wang and J.C. Travers, Laser & Photonics Reviews 16, 2100426 (2022)
• We followed closely: Phys. Rev. A, vol. 92, no. 6, p. 063828, Dec. 2015, But note that that paper uses weird units, and we converted it to SI for the above reference.

hrdamp(R::AbstractRamanResponse, ρ)

Get the damping (dephasing) constant τ2 for density ̢ρ.

hrpre(R::AbstractRamanResponse, t)

Get the pre (without damping) response function at time t.

molecular_raman_response(rp; kwargs...)

Get the Raman response function for the Raman parameters in named tuple rp.

Keyword Arguments

• rotation::Bool = true: whether to include the rotational contribution
• vibration::Bool = true: whether to include the vibrational contribution
• minJ::Integer = 0: the minimum rotational quantum number to include
• maxJ::Integer = 50: the maximum rotational quantum number to include
• temp::Real = roomtemp: the temperature

raman_response(t, material; kwargs...)

Get the Raman response function for time grid t and the material.

For details on the keyword arguments see molecular_raman_response.