Wavelength shifting in fiber (absorption length)

Dear Geant4 users,

I have a problem which concerns optical wavelength shifting simulation in fiber. I cannot understand how it is rigth to set an absorption length for fiber. I want to set this length to 217 cm for example (let’s assume it does’t depend on wave of comming photons). So when I did the following (below), that works fine, but the absorption length is not right.

Code

G4double PhotonEnergy_PS_ABS[nEntries_PS_1] = {3.539eV, 3.477eV, 3.340eV, 3.321eV, 3.291eV, 3.214eV, 3.162eV, 3.129eV, 3.091eV, 3.086eV, 3.049eV, 3.008eV, 2.982eV, 2.958eV, 2.928eV, 2.905eV, 2.895eV, 2.890eV, 2.858eV, 2.813eV, 2.774eV, 2.765eV, 2.752eV, 2.748eV, 2.739eV, 2.735eV, 2.731eV, 2.723eV, 2.719eV, 2.698eV, 2.674eV, 2.626eV, 2.610eV, 2.583eV, 2.556eV, 2.530eV, 2.505eV, 2.480eV, 2.455eV, 2.431eV, 2.407eV, 2.384eV };

G4double RIndexFiber_PS[nEntries_PS_1] = {1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59, 1.59};

G4double AbsFiber_PS[nEntries_PS_1] = {0.28cm, 0.28cm, 0.26cm, 0.25cm, 0.24cm, 0.21cm, 0.19cm, 0.16cm, 0.13cm, 0.13cm, 0.14cm, 0.11cm, 0.08cm, 0.05cm, 0.02cm, 0.05cm, 0.08cm, 0.10cm, 0.13cm, 0.10cm, 0.08cm, 0.07cm, 0.08cm, 0.11cm, 0.13cm, 0.16cm, 0.19cm, 0.21cm, 0.24cm, 0.27cm, 0.30cm, 2.69cm, 3.49cm, 3.99cm, 5.00cm, 8.6cm, 11.6cm, 23.1cm, 55cm, 93cm, 317cm, 494cm};

G4double PhotonEnergy_PS_EM[nEntries_PS] = {2.69eV, 2.67eV, 2.66eV, 2.64eV, 2.63eV, 2.61eV, 2.58eV, 2.56eV, 2.55eV, 2.53eV, 2.50eV, 2.48eV, 2.46eV, 2.45eV, 2.44eV, 2.43eV, 2.41eV, 2.37eV, 2.33eV, 2.25eV, 2.24eV, 2.19eV, 2.15eV, 2.08eV };

G4double EmissionFiber_PS[nEntries_PS] = {0, 0.02, 0.09, 0.20, 0.29, 0.40, 0.59, 0.70, 0.80, 0.89, 1.00, 0.96, 0.88, 0.79, 0.69, 0.59, 0.50, 0.40, 0.31, 0.22, 0.19, 0.10, 0.06, 0};

But when I change AbsFiber_PS to:

Changed AbsFiber_PS

G4double AbsFiber_PS[nEntries_PS_1] = {217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm, 217cm};

there is no wavelength shigting at all. Don’t understand why? So, could someone please tell how to set absorption length in fiber to 217 cm for example in right way?

Thank you in advance!

First of all ty to add “*” between value and unit. It appears to me that you have huge emittance and absorbance overlay from the first view.

matus

Thank you for your reply. Actually I have *. That came from copy and past. In source code everything sis ok.

The problem was solved.