Procedure for modeling core pumped fibers

[skynet-programmer69]

Hi Yi-Hao,

I wanted to check with you if my procedure for modeling core pumped fibers is correct. For most of your examples it looks to me as if you have the manufacturer numbers for cladding pumped absorption at a specific wavelength, but some fiber specs only give core pumped absorption numbers. In this case I typically set the cladding size to the core size and use the specified absorption number, then manually set the MFD for the particular fiber. This method seems a bit too ad hoc for me but seems to lead to more expected results.

Is this the procedure that you would recommend? Apologizes if this is a silly question, I'm an experimentalist who likes to dabble in modeling and am by no means an expert ;P

Thanks!

[AaHaHaa]

Haha, I'm in principle an experimentalist too. I just do more thinking and publish more theoretical works recently.

My code assumes double-cladding fiber.
If you're using a single-cladding (core-pumped) fiber, then you're right: set the cladding size the same as core size and set the cladding absorption as the core absorption in the manufacturer's specs (since it's the same as core now).

This is what I did in my single-mode ANDi oscillator code. See Examples/Dissipative soliton (ANDI oscillator) or soliton laser/Single-mode dissipative soliton/ANDi_rate_eqn_gain_Yb_woASE.m (or other similar examples in this folder).

If you want to go into the rate-gain details, cladding size and core size determine the overlap factor between the pump and the doped core, which further affects how fast the pump is depleted. In core-pumped fiber, overlap factor = 1, so just set cladding diameter = core diameter.

[skynet-programmer69]

Thanks for the answer! Awesome that you are writing such great code with an experimentalist background. The knowledge of both sides really compliments a study in a nonlinear way!

All the best.