MULTEM 2: a new version of the program for transmission and band- structure calculations of photonic crystals. N. Stefanou, V. Yannopapas, A. Modinos.

PROGRAM SUMMARY
Title of program: MULTEM, version 2
Catalogue identifier: ADMQ
Ref. in CPC: 132(2000)189
Distribution format: gzip file
Operating system: HP-UX 10.20,IRIX6.2,Red Hat LINUX 5.2,MS Windows
High speed store required: 1MK words
Number of bits in a word: 32
Number of lines in distributed program, including test data, etc: 4545
Keywords: Photonic crystals, Complex photonic band structure, Transmission and reflection coefficients, Multiple scattering of electromagnetic waves.
Programming language used: Fortran
Computer: HP 9000/778/B180L , SGI Indy IP22/150MHz , Pentium PC .

Other versions of this program:

 Cat. Id.  Title                             Ref. in CPC
 ADIM      MULTEM                             113(1998)49                    
 

Nature of physical problem:
Calculation of the complex band structure associated with a given surface of a photonic crystal, and of the transmission, reflection and absorption coefficients of light by a slab of the crystal parallel to the given surface. We note that the ordinary frequency band structure of the infinite crystal is contained within the complex band structure of any surface of the crystal.

Method of solution:
Solution of Maxwell's equations using multiple-scattering techniques.

Restrictions:
The structures that can be considered consist of parallel planes of non-overlapping spheres of given two-dimensional periodicity and uniform plates.

Typical running time:
For the same problem (test run in Ref. [1]) the time required on an HP 9000/778/B180L workstation by the present version is about 1.5s (2.4s) per frequency for the band-structure (transmission) calculation, instead of 20.3s (49.6s) required by the previous version. The input and results are the same and are not reproduced here.

Summary of revisions:

1. In the expansion of the electromagnetic field into plane waves we now use a basis of transverse plane waves, thus excluding from the beginning unphysical longitudinal solutions. In this way the dimensions of the reflection/transmission matrices are reduced by a factor of 3/2. For this purpose, subroutines DLMKG, HOSLAB, and PLW have been modified, with consequent amendments in other subroutines and in the main program.
2. In relation to a transmission calculation, the new version of the program makes it possible to have different semi-infinite homogeneous media on the left and right sides of the slab of the crystal. For this purpose appropriate changes have been made in the main program and in subroutine SCAT. For KEMB=1, in the last two lines of the input data file for a transmission calculation, we give the values of the dielectric constants and magnetic permeabilities of the media on the left and right sides of the slab.
3. The matrix-multiplication operations in subroutine PAIR are written in a more efficient way thus leading to a considerable speed-up in the execution of the program.
4. A few mistakes of minor importance and inconsistencies, leading to warning or error messages in some Fortran compilers, have been corrected.

References:

 [1] N. Stefanou, V. Yannopapas, and A. Modinos, Comput. Phys. Commun.   
     113 (1998) 49.