OPTIMAL DESIGN OF GRADED REFRACTIVE INDEX PROFILE FOR BROADBAND OMNIDIRECTIONAL ANTIREFLECTION COATINGS USING GENETIC PROGRAMMING

To eliminate the average re∞ectance of antire∞ection coatings to the greatest extent, a Genetic Programming (GP) algorithm is proposed to design and optimize the graded refractive index distribution proflle for broadband omnidirectional antire∞ection coatings. The proposed GP-index proflle in this paper can obtain an extremely low average re∞ectance of 4:61£10 i7 % over a wide range of incident angles and wavelengths which is obviously superior to the average re∞ectance of 8:09£10 i3 %, 3:29£10 i4 % and 4:35£10 i5 % for linear proflle, cubic proflle and quintic proflle. That means, Fresnel re∞ection almost can be eliminated by the optimal GP-index proflle for omnidirectional incidence over a broad wavelength range. Moreover, it is demonstrated the proposed GP-index proflle has better robustness, and it still has the best broadband and omnidirectional antire∞ection characteristics for the TiO2/SiO2 graded-index AR coating. Therefore, the proposed GP-index proflle is obviously superior to the conventional linear proflle, cubic proflle and quintic proflle, and the design methodology presented in this paper that uses a genetic programming technique is a quite convenient means to pursue an optimal nonlinear refractive index proflle with broadband and omnidirectional antire∞ection characteristics.

[1]  Q. Shen,et al.  Light-trapping design of graphene transparent electrodes for efficient thin-film silicon solar cells. , 2012, Applied optics.

[2]  Theodor Tamir,et al.  Modal transmission-line theory of multilayered grating structures , 1996 .

[3]  Na Li,et al.  The Microstructure Design Optimization of Negative Index Metamaterials Using Genetic Algorithm , 2011 .

[4]  Katherine Siakavara,et al.  NOVEL FRACTAL ANTENNA ARRAYS FOR SATELLITE NETWORKS: CIRCULAR RING SIERPINSKI CARPET ARRAYS OPTIMIZED BY GENETIC ALGORITHMS , 2010 .

[5]  Penghui Ma,et al.  Toward perfect antireflection coatings: numerical investigation. , 2002, Applied optics.

[6]  Daniel Poitras,et al.  Toward perfect antireflection coatings. 2. Theory. , 2004, Applied optics.

[7]  Hung-chun Chang,et al.  Design of optical path for wide-angle gradient-index antireflection coatings. , 2007, Applied optics.

[8]  S. V. Savov,et al.  Modal transmission-line modeling of propagation of plane radiowaves through multilayer periodic building structures , 2003 .

[9]  Qiang Shen,et al.  Optimizing low loss negative index metamaterial for visible spectrum using differential evolution. , 2011, Optics express.

[10]  John R. Koza,et al.  Genetic programming - on the programming of computers by means of natural selection , 1993, Complex adaptive systems.

[11]  W H Southwell,et al.  Gradient-index antireflection coatings. , 1983, Optics letters.

[12]  Yin-Jung Chang,et al.  Broadband omnidirectional antireflection coatings for metal-backed solar cells optimized using simulated annealing algorithm incorporated with solar spectrum. , 2011, Optics express.

[13]  Q. Shen,et al.  Optimal design of light trapping in thin-film solar cells enhanced with graded SiNx and SiOxNy structure. , 2012, Optics express.

[14]  Carlos A. Brizuela,et al.  A Comparison of Genetic Algorithms, Particle Swarm Optimization and the Differential Evolution Method for the Design of Scannable Circular Antenna Arrays , 2009 .

[15]  Theodor Tamir,et al.  Modal transmission-line theory of three-dimensional periodic structures with arbitrary lattice configurations. , 2002, Journal of the Optical Society of America. A, Optics, image science, and vision.

[16]  Lord Rayleigh,et al.  On Reflection of Vibrations at the Confines of two Media between which the Transition is Gradual , 1879 .

[17]  Q. Shen,et al.  Optimizing low loss silver nanowires structure metamaterial at yellow light spectrum with differential evolution , 2012 .

[18]  M. Brett,et al.  Porous broadband antireflection coating by glancing angle deposition. , 2003, Applied optics.

[20]  W. Southwell.  Pyramid-array surface-relief structures producing antireflection index matching on optical surfaces , 1991 .