July 15, 2009

PyOSSMGPU

The propagation of high-intensity laser pulses in fiber bragg grating or in any nonlinear periodic dielectric media can be studied using coupled-mode theory. When applied to Bragg grating in optical fiber, the coupled-mode theory lead to two coupled-mode equations which can be numerically resolved using a classical fourth-order Runge-Kutta formula. When studying classical problem like propagation of bragg soliton in very long grating (many cm), Runge-Kutta method usually take many hours to complete. PyOSSMGPU is a CUDA implementation of the optimized split-step method for solving nonlinear coupled-mode equations that model wave propagation in nonlinear fiber Bragg gratings. The GPU accelerated version of the OSSM code perform around 73X faster then plain C version. Classical problem like bragg soliton in very long grating take can be completed typically within a minute.

i\frac{\partial A_f}{\partial z} + {\frac{1}{v_g} \frac{\partial A_f}{\partial t}} + \delta A_f +\kappa A_b + \gamma(|A_f|^2 + 2|A_b|^2 )A_f =0

i\frac{\partial A_b}{\partial z} +{\frac{1}{v_g} \frac{\partial A_b}{\partial t}}+ \delta A_b +\kappa A_f + \gamma(|A_b|^2 + 2|A_f|^2 )A_b =0

If you are interested by this software you can contact me

Example 1: Propagation of a single bragg soliton in a uniform grating


Example 2: Figure 10(b) of Litchinitser et al (1997 ) computed using  PyOSSMGPU.

NM Litchinitser and DB Patterson. Analysis of fiber Bragg gratings for dispersion compensation inreflective and transmissive geometries. Lightwave Technology,
Journal of, 15(8) :13231328, 1997.

GeForce GTX 260 processing time: 12.0 sec.
Intel Quad-Core 3.2 Ghz (1 core): 15 min. (879 sec.)
Speedup: 73X


Example 3: Propagation of a single bragg soliton in a uniform grating


Example 4: Same parameters as example 3 but without nonlinearity