Self Steepening - modifying the shock time

[Lucy Hooper]

Hi,

I am trying to re-create figure 3 from "Dudley, J. M. et al., 2006.
Supercontinuum generation in photonic crystal fiber. Rev. Mod. Phys,
78, 1135-1184" , using Fiberdesk.

I am having problems with the self steepening. I want to input the
shock timescale to be equal to 0.56 fs. To do this I thought that I
needed to put additional shock time "tau_A" into the fiber parameter
dialogue box in Fiberdesk, and that this tau_A needed to be 0.56 fs -
1/w0 = 0.117 fs in my case (wavelength = 835 nm).

I have been comparing the Fiberdesk results to the results from a
simple code in Matlab which uses a split step method to solve the same
GNLSE given in the fiberdesk manual. When I set the shock time to 0.56
fs in the Matlab code, and put tau_A = 0.117 fs in Fiberdesk, the
results are different - the Fiberdesk soliton does not shift as far.
However, when I set tau_A = 0 in Fiberdesk and set shock time to 1/w0
in the Matlab code, the results are the same (ie. the soliton shifts
to the same wavelength).

It also turns out that if halve the additional shock time in Fiberdesk
ie. I put tau_A = 0.0585 fs, this result matches that from tau_shock =
0.56 fs in the matlab code. Similarly, the results agree when setting
tau_A to 0.117 fs in Fiberdesk and setting tau_shock to 0.677 fs in
Matlab (equivalent to 1/w0 + 2*0.117fs)

So, either
1) There is a factor of two amiss in the additional shock term in
fiberdesk
2) It's just a co-incidence that my fudge worked and my other code is
wrong
3) I have misunderstood how to put in the shock parameter in the first
place

Any help with this would be greatly appreciated!

Cheers
Lucy

--
Lucy Hooper
Postgraduate Student
Centre for Photonics and Photonic Materials
Department of Physics
University of Bath

L.E.H...@bath.ac.uk
+44 1225 385007

[FiberDesk]

Dear Lucy,

thank you for your remark,
I'll check the numerical code for the shock term and come back to this
issues as soon as possible.

best regards,

Thomas

> L.E.Hoo...@bath.ac.uk
> +44 1225 385007