It is well known that high refractive index contrast is essential to the formation of an omnidirectional Photonic Band Gap (PBG). It is generally cited also that the width of the omnidirectional PBG of a dielectric mirror is determined by the refractive-index contrast. But in this work, we show that this condition is not really general criteria. Dielectric mirror with higher refractive index contrast does not necessarily mean that it has the largest omnidirectional photonic band gap. So, we investigate the necessary conditions on the high and low refractive indices of the quarter wave layers to have the largest omnidirectional bandwidth in the visible range. We present a profound study of the omnidirectional band center wavelength and the bandwidth behaviors versus the layers refraction indices. It is shown therefore that one can modulate omnidirectional photonic band gap center by modulating the optical phase of the mirror.
2. Mouldi, A. and M. Kanzari, "Broad multilayer antireflection coating by apodized and chirped photonic crystal," Optics Communications, Vol. 284, 4124-4128, 2011.
3. Qiang, H., L. Jiang, and X. Li, "Design of broad omnidirectional total reflectors based on onedimensional dielectric and magnetic photonic crystals," Optics & Laser Technology, Vol. 42, 105-109, 2010.
4. Srivastava, R. and S. P. Ojha, "Enhancement of omnidirectional Reflection bands in onedimensional photonic crystals with left-handed materials," Progress In Electromagnetics Research, Vol. 68, 91-111, 2007.
5. Fink, Y., J. N. Winn, S. Fan, C. Chen, J. Michel, J. D. Joannopoulos, and E. L. Thomas, "A dielectric omnidirectional reflector," Science, Vol. 282, 1679-1682, 1998.
6. Deopura, M., C. K. Ullal, B. Temelkuran, and Y. Fink, "Dielectric omnidirectional visible reflector," Opt. Lett., Vol. 26, 1197-1199, 2001.
7. Han, P. and H. Wang, "Extension of omnidirectional reflection range in one-dimensional photonic crystals with a staggered structure," J. Opt. Soc. Am. B, Vol. 20, 1996-2001, 2003.
8. Joannopoulos, J. D., S. G. Johnson, J. N. Winn, and R. D. Meade, Molding the Flow of Light, 2nd Ed., 2007.
9. Bananej, A., S. M. Hamidi, W. Li, C. Li, and M. M. Tehranchi, "A flexible design for one-dimensional photonic crystals with controllable photonic bandgap width," Optical Materials, Vol. 30, No. 12, 1822-1827, 2008.
10. Sang, Z. F. and Z. Y. Li, "Optical properties of one-dimensional photonic crystals containing graded material," Optics Communications, Vol. 259, 174-178, 2006.
11. Galindo-Linaresa, E., P. Halevia, and A. S. Sanchez, "Tuning of one-dimensional Si/SiO2 photonic crystals at the wavelength of 1.54 μm," Solid State Communications, Vol. 142, 67-70, 2007.
12. Singh, S. K., J. P. Pandey, K. B. Thapa, and S. P. Ojha, "Structural parameters in the formation of omnidirectional high reflectors," Progress In Electromagnetics Research, Vol. 70, 53-78, 2007.
13. Wang, Z. and D. Liu, "A few points on omnidirectional band gaps in one-dimensional photonic crystals," Appl. Phys. B, Vol. 86, 473-476, 2007.
14. Southwell, W. H., "Omnidirectional mirror design with quarter-wave dielectric stacks," Appl. Opt., Vol. 38, 5464-5467, 1999.
15. Lekner, J., "Omnidirectional reflection by multilayer dielectric mirrors," J. Opt. A: Pure Appl. Opt., Vol. 2, 349-352, 2000.
16. Li, Z., "Principles of the plane-wave transfer-matrix method for photonic crystals," Science and Technology of Advanced Materials, Vol. 6, 837-841, 2005.
17. Abeles, F., Ann Phys. Paris, Vol. 12, 596, 1950.
18. Tehranchi, A. and R. Kashyap, "Novel step-chirped quasi-phase matched gratings for broadband frequency doublers with high-efficiency flat response in nonlinear optical waveguides," 19th General Assembly, 47-51, Chicago, USA, August 7–16, 2008.
19. Bi, G. and H. Wang, "A theoretical study of the chirped and apodized photonic crystals," PIERS Proceedings, 571-574, Hangzhou, China, August 22–26, 2005.
20. Mouldi, A. and M. Kanzari, "Design of an omnidirectional mirror using one dimensional photonic crystal with graded geometric layers thicknesses," OPTIK, Vol. 123, 125-131, 2012.