Silica Optical Fiber Technology for Devices and Components: Design, Fabrication, and International Standards

APPENDIX B

Operation Manual of OFACAD

B.1   CONVENTIONALSTEPINDEXSINGLEMODE FIBER SIMULATION

As shown in Figure B. 1, choose “SMF28.idx” from the default index profiles and then click “OK.” In OFACAD_EDU main page, click “OK” from “Index Profiles Setup” that is shown in Figure B.2.

Related refractive index profile will appear as shown in Figure B.3.

As indicated in Figure B.3, mode should be selected now. This program gives the facility to choose HE, TE, TM, and EH modes. Let us choose HE_11, which is the fundamental mode, as shown in Figure B.4, and then click “OK.”

Now it is the appropriate time to check for the cutoff wavelength. The wavelength at which a mode ceases to propagate is called the cutoff wavelength for that mode. Usually just TE_01 mode is checked for cutoff wavelength. Click “OK” button (Figure B.5).

B.1.1   Material Property

Choose “Material property” from “Config” in the menu bar. Press “OK” button. The plot is demonstrated in Figure B.6. By putting wavelength in the upper part, refractive index profile of pure silica will be defined. Here for wavelength equal to 0.6328 μm, refractive index of pure silica is 1.4570179.

B.1.2   Effective Index versus Wavelength (μm)

Choose “Effective Index” from “Viewer” in menu tab. Then press “OK.” And then curve of “Effective Index” versus wavelength of related refractive index profile is plotted. By clicking on each point of the curve, its “wavelength” and also “Effective index” will be shown in the box located at the bottom ...