GD-Calc computes diffraction efficiencies and polarization characteristics (multi-order transmission and reflection) of line gratings, biperiodic gratings, and multilayer-stack gratings with any number of layers and materials (dielectric or metallic).
The diffraction grating simulation algorithms are based on Rigorous Coupled-Wave Theory (RCWA), aka. the "Fourier Modal Method" (FMM), using a 3-D generalization of Li's Fast Fourier Factorization method. The code is limited to non-magnetic, isotropic, linear optical media, and the algorithms are based on a block-structured geometry model (i.e. grating structures are decomposed into homogeneous, rectangular blocks). Curved and tapered surfaces can be approximated using the "staircase approximation", which is routinely used for dielectric gratings, although the approximation can create convergence difficulties with highly conducting metal gratings.
GD-Calc is implemented entirely in MATLAB®, providing a convenient, user-modifiable functional interface, and making it easy to incorporate grating components in custom optical design and simulation models. Standard MATLAB utilities such as fminsearch and the Global Optimization Toolbox can be adapted for grating design. Also, GD-Calc has a powerful "vectorization" capability for efficiently performing multi-dimensional parameter sweeps, e.g., as part of a global search process.
Explore the online documentation and free demo code to test GD-Calc's diffraction grating simulation capabilities; run the GD-Calc data validation and plotting functions on your grating structure of interest; and then purchase the P-code calculation engine module to access GD-Calc's full computational capabilities.
Install all files (except the pdf's) on your
MATLAB path. (Note: *.m files are MATLAB source code, the *.p file is
MATLAB-encrypted p-code, and *.nk files are text.)
2, Test: First skim through GD‑Calc_Intro.pdf to
learn the basics of how grating geometry is specified in GD‑Calc. (The
code examples are in gdc_intro.m, which requires gdc.m and gdc_plot.m.
Each code listing builds on previous listings, so run them in order.)
Then review GD‑Calc_Demo.pdf for a more extensive introduction with
examples of diffraction calculations, and test the performance of the
demo scripts on your computer. Set up your grating model of interest
and run it through gdc.m (with no output arguments) and gdc_plot.m to
check data validity and visually confirm model correctness.
3, Purchase: Purchase the calculation engine to
access the full functionality of GD-Calc for diffraction grating simulation:
5/12/2005. Price: $550.
(Note: A quantity-1 order is licensed to run concurrently on 2
computers. A quantity-N order is licensed to run on 2*N computers.)