A. K. Popov and V. M. Shalaev, "Compensating losses in negative-index metamaterials by optical parametric amplification," Opt. Lett. 31, 2169-2171 (2006).

[Crossref]
[PubMed]

P. Schmidt, S. Haas, and A. F. J. Levi, "Synthesis of electron transmission in nanoscale semiconductor devices," Appl. Phys. Lett. 88, 013502 (2006).

[Crossref]

A. Gondarenko, S. Preble, J. Robinson, L. Chen, H. Lipson, and M. Lipson, "Spontaneous emergence of periodic patterns in a biologically inspired simulation of photonic structures," Phys. Rev. Lett. 96, 143904 (2006).

[Crossref]
[PubMed]

A. Hakansson, H. T. Miyazaki, and J. Sánchez-Dehesa, "Inverse design for full control of spontaneous emission using light emitting scattering optical elements," Phys. Rev. Lett. 96, 153902 (2006).

[Crossref]
[PubMed]

V. Dudiy and A. Zunger, "Searching for alloy configurations with target physical properties: impurity design via a genetic algorithm inverse band structure approach," Phys. Rev. Lett. 97, 046401 (2006).

[Crossref]
[PubMed]

V. M. Shalaev, W. Cai, U. K. Chettiar, H. K. Yuan, A. K. Sarychev, V. P. Drachev, and A. Kildishev, "Negative index of refraction in optical metamaterials," Opt. Lett. 30, 3356-3358 (2005).

[Crossref]

A. N. Grigorenko, A. K. Geim, H. F. Gleeson, Y. Zhang, A. A. Firsov, I. Y. Khrushchev, and J. Petrovic, "Nanofabricated media with negative permeability at visible frequencies," Nature 438, 335-338 (2005).

[Crossref]
[PubMed]

N. Engheta, "An idea for thin subwavelength cavity resonators using metamaterials with negative permittivity and permeability," IEEE Antennas Propag. Mag. 1, 10-13 (2002).

J. B. Pendry, "Negative refraction makes a perfect lens," Phys. Rev. Lett. 85, 3966-3969 (2000).

[Crossref]
[PubMed]

D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, "Composite medium with simultaneously negative permeability and permittivity," Phys. Rev. Lett. 84, 4184-4187 (2000).

[Crossref]
[PubMed]

While not applicable to the subwavelength structures considered here, we note that an effective negative refractive index may also be achieved using photonic crystal dielectric material as discussed by M. Notomi, "Theory of light propagation in strongly modulated photonic crystals: refractionlike behavior in the vicinity of the photonic band gap," Phys. Rev. B 62, 10696-10705 (2000).

[Crossref]

J. B. Pendry, A. J. Holden, D. J. Robbins, and W. J. Stewart, "Magnetism from conductors and enhanced nonlinear phenomena," IEEE Trans. Microwave Theory Tech. 47, 2075 (1999).

[Crossref]

K. R. Gegenfurtner, "PRAXIS: Brent's algorithm for function minimization," Behav. Res. Methods Instrum. 24, 560-564 (1993).

V. G. Veselago, "The electrodynamics of substances with simultaneously negative values of epsi and μ," Sov. Phys. Usp. 10, 509-514 (1968).

[Crossref]

R. P. Brent, Algorithms for Minimization Without Derivatives (Dover, 2002).

A. Gondarenko, S. Preble, J. Robinson, L. Chen, H. Lipson, and M. Lipson, "Spontaneous emergence of periodic patterns in a biologically inspired simulation of photonic structures," Phys. Rev. Lett. 96, 143904 (2006).

[Crossref]
[PubMed]

V. Dudiy and A. Zunger, "Searching for alloy configurations with target physical properties: impurity design via a genetic algorithm inverse band structure approach," Phys. Rev. Lett. 97, 046401 (2006).

[Crossref]
[PubMed]

N. Engheta, "An idea for thin subwavelength cavity resonators using metamaterials with negative permittivity and permeability," IEEE Antennas Propag. Mag. 1, 10-13 (2002).

A. N. Grigorenko, A. K. Geim, H. F. Gleeson, Y. Zhang, A. A. Firsov, I. Y. Khrushchev, and J. Petrovic, "Nanofabricated media with negative permeability at visible frequencies," Nature 438, 335-338 (2005).

[Crossref]
[PubMed]

K. R. Gegenfurtner, "PRAXIS: Brent's algorithm for function minimization," Behav. Res. Methods Instrum. 24, 560-564 (1993).

A. N. Grigorenko, A. K. Geim, H. F. Gleeson, Y. Zhang, A. A. Firsov, I. Y. Khrushchev, and J. Petrovic, "Nanofabricated media with negative permeability at visible frequencies," Nature 438, 335-338 (2005).

[Crossref]
[PubMed]

A. N. Grigorenko, A. K. Geim, H. F. Gleeson, Y. Zhang, A. A. Firsov, I. Y. Khrushchev, and J. Petrovic, "Nanofabricated media with negative permeability at visible frequencies," Nature 438, 335-338 (2005).

[Crossref]
[PubMed]

A. Gondarenko, S. Preble, J. Robinson, L. Chen, H. Lipson, and M. Lipson, "Spontaneous emergence of periodic patterns in a biologically inspired simulation of photonic structures," Phys. Rev. Lett. 96, 143904 (2006).

[Crossref]
[PubMed]

A. N. Grigorenko, A. K. Geim, H. F. Gleeson, Y. Zhang, A. A. Firsov, I. Y. Khrushchev, and J. Petrovic, "Nanofabricated media with negative permeability at visible frequencies," Nature 438, 335-338 (2005).

[Crossref]
[PubMed]

P. Schmidt, S. Haas, and A. F. J. Levi, "Synthesis of electron transmission in nanoscale semiconductor devices," Appl. Phys. Lett. 88, 013502 (2006).

[Crossref]

A. Hakansson, H. T. Miyazaki, and J. Sánchez-Dehesa, "Inverse design for full control of spontaneous emission using light emitting scattering optical elements," Phys. Rev. Lett. 96, 153902 (2006).

[Crossref]
[PubMed]

J. B. Pendry, A. J. Holden, D. J. Robbins, and W. J. Stewart, "Magnetism from conductors and enhanced nonlinear phenomena," IEEE Trans. Microwave Theory Tech. 47, 2075 (1999).

[Crossref]

A. N. Grigorenko, A. K. Geim, H. F. Gleeson, Y. Zhang, A. A. Firsov, I. Y. Khrushchev, and J. Petrovic, "Nanofabricated media with negative permeability at visible frequencies," Nature 438, 335-338 (2005).

[Crossref]
[PubMed]

P. Schmidt, S. Haas, and A. F. J. Levi, "Synthesis of electron transmission in nanoscale semiconductor devices," Appl. Phys. Lett. 88, 013502 (2006).

[Crossref]

A. Gondarenko, S. Preble, J. Robinson, L. Chen, H. Lipson, and M. Lipson, "Spontaneous emergence of periodic patterns in a biologically inspired simulation of photonic structures," Phys. Rev. Lett. 96, 143904 (2006).

[Crossref]
[PubMed]

A. Gondarenko, S. Preble, J. Robinson, L. Chen, H. Lipson, and M. Lipson, "Spontaneous emergence of periodic patterns in a biologically inspired simulation of photonic structures," Phys. Rev. Lett. 96, 143904 (2006).

[Crossref]
[PubMed]

A. Hakansson, H. T. Miyazaki, and J. Sánchez-Dehesa, "Inverse design for full control of spontaneous emission using light emitting scattering optical elements," Phys. Rev. Lett. 96, 153902 (2006).

[Crossref]
[PubMed]

D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, "Composite medium with simultaneously negative permeability and permittivity," Phys. Rev. Lett. 84, 4184-4187 (2000).

[Crossref]
[PubMed]

While not applicable to the subwavelength structures considered here, we note that an effective negative refractive index may also be achieved using photonic crystal dielectric material as discussed by M. Notomi, "Theory of light propagation in strongly modulated photonic crystals: refractionlike behavior in the vicinity of the photonic band gap," Phys. Rev. B 62, 10696-10705 (2000).

[Crossref]

D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, "Composite medium with simultaneously negative permeability and permittivity," Phys. Rev. Lett. 84, 4184-4187 (2000).

[Crossref]
[PubMed]

J. B. Pendry, "Negative refraction makes a perfect lens," Phys. Rev. Lett. 85, 3966-3969 (2000).

[Crossref]
[PubMed]

J. B. Pendry, A. J. Holden, D. J. Robbins, and W. J. Stewart, "Magnetism from conductors and enhanced nonlinear phenomena," IEEE Trans. Microwave Theory Tech. 47, 2075 (1999).

[Crossref]

A. N. Grigorenko, A. K. Geim, H. F. Gleeson, Y. Zhang, A. A. Firsov, I. Y. Khrushchev, and J. Petrovic, "Nanofabricated media with negative permeability at visible frequencies," Nature 438, 335-338 (2005).

[Crossref]
[PubMed]

A. Gondarenko, S. Preble, J. Robinson, L. Chen, H. Lipson, and M. Lipson, "Spontaneous emergence of periodic patterns in a biologically inspired simulation of photonic structures," Phys. Rev. Lett. 96, 143904 (2006).

[Crossref]
[PubMed]

J. B. Pendry, A. J. Holden, D. J. Robbins, and W. J. Stewart, "Magnetism from conductors and enhanced nonlinear phenomena," IEEE Trans. Microwave Theory Tech. 47, 2075 (1999).

[Crossref]

A. Gondarenko, S. Preble, J. Robinson, L. Chen, H. Lipson, and M. Lipson, "Spontaneous emergence of periodic patterns in a biologically inspired simulation of photonic structures," Phys. Rev. Lett. 96, 143904 (2006).

[Crossref]
[PubMed]

A. Hakansson, H. T. Miyazaki, and J. Sánchez-Dehesa, "Inverse design for full control of spontaneous emission using light emitting scattering optical elements," Phys. Rev. Lett. 96, 153902 (2006).

[Crossref]
[PubMed]

P. Schmidt, S. Haas, and A. F. J. Levi, "Synthesis of electron transmission in nanoscale semiconductor devices," Appl. Phys. Lett. 88, 013502 (2006).

[Crossref]

D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, "Composite medium with simultaneously negative permeability and permittivity," Phys. Rev. Lett. 84, 4184-4187 (2000).

[Crossref]
[PubMed]

A. K. Popov and V. M. Shalaev, "Compensating losses in negative-index metamaterials by optical parametric amplification," Opt. Lett. 31, 2169-2171 (2006).

[Crossref]
[PubMed]

V. M. Shalaev, W. Cai, U. K. Chettiar, H. K. Yuan, A. K. Sarychev, V. P. Drachev, and A. Kildishev, "Negative index of refraction in optical metamaterials," Opt. Lett. 30, 3356-3358 (2005).

[Crossref]

D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, "Composite medium with simultaneously negative permeability and permittivity," Phys. Rev. Lett. 84, 4184-4187 (2000).

[Crossref]
[PubMed]

J. B. Pendry, A. J. Holden, D. J. Robbins, and W. J. Stewart, "Magnetism from conductors and enhanced nonlinear phenomena," IEEE Trans. Microwave Theory Tech. 47, 2075 (1999).

[Crossref]

V. G. Veselago, "The electrodynamics of substances with simultaneously negative values of epsi and μ," Sov. Phys. Usp. 10, 509-514 (1968).

[Crossref]

D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, "Composite medium with simultaneously negative permeability and permittivity," Phys. Rev. Lett. 84, 4184-4187 (2000).

[Crossref]
[PubMed]

A. N. Grigorenko, A. K. Geim, H. F. Gleeson, Y. Zhang, A. A. Firsov, I. Y. Khrushchev, and J. Petrovic, "Nanofabricated media with negative permeability at visible frequencies," Nature 438, 335-338 (2005).

[Crossref]
[PubMed]

V. Dudiy and A. Zunger, "Searching for alloy configurations with target physical properties: impurity design via a genetic algorithm inverse band structure approach," Phys. Rev. Lett. 97, 046401 (2006).

[Crossref]
[PubMed]

P. Schmidt, S. Haas, and A. F. J. Levi, "Synthesis of electron transmission in nanoscale semiconductor devices," Appl. Phys. Lett. 88, 013502 (2006).

[Crossref]

K. R. Gegenfurtner, "PRAXIS: Brent's algorithm for function minimization," Behav. Res. Methods Instrum. 24, 560-564 (1993).

N. Engheta, "An idea for thin subwavelength cavity resonators using metamaterials with negative permittivity and permeability," IEEE Antennas Propag. Mag. 1, 10-13 (2002).

J. B. Pendry, A. J. Holden, D. J. Robbins, and W. J. Stewart, "Magnetism from conductors and enhanced nonlinear phenomena," IEEE Trans. Microwave Theory Tech. 47, 2075 (1999).

[Crossref]

A. N. Grigorenko, A. K. Geim, H. F. Gleeson, Y. Zhang, A. A. Firsov, I. Y. Khrushchev, and J. Petrovic, "Nanofabricated media with negative permeability at visible frequencies," Nature 438, 335-338 (2005).

[Crossref]
[PubMed]

V. M. Shalaev, W. Cai, U. K. Chettiar, H. K. Yuan, A. K. Sarychev, V. P. Drachev, and A. Kildishev, "Negative index of refraction in optical metamaterials," Opt. Lett. 30, 3356-3358 (2005).

[Crossref]

A. K. Popov and V. M. Shalaev, "Compensating losses in negative-index metamaterials by optical parametric amplification," Opt. Lett. 31, 2169-2171 (2006).

[Crossref]
[PubMed]

While not applicable to the subwavelength structures considered here, we note that an effective negative refractive index may also be achieved using photonic crystal dielectric material as discussed by M. Notomi, "Theory of light propagation in strongly modulated photonic crystals: refractionlike behavior in the vicinity of the photonic band gap," Phys. Rev. B 62, 10696-10705 (2000).

[Crossref]

J. B. Pendry, "Negative refraction makes a perfect lens," Phys. Rev. Lett. 85, 3966-3969 (2000).

[Crossref]
[PubMed]

D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, "Composite medium with simultaneously negative permeability and permittivity," Phys. Rev. Lett. 84, 4184-4187 (2000).

[Crossref]
[PubMed]

A. Gondarenko, S. Preble, J. Robinson, L. Chen, H. Lipson, and M. Lipson, "Spontaneous emergence of periodic patterns in a biologically inspired simulation of photonic structures," Phys. Rev. Lett. 96, 143904 (2006).

[Crossref]
[PubMed]

A. Hakansson, H. T. Miyazaki, and J. Sánchez-Dehesa, "Inverse design for full control of spontaneous emission using light emitting scattering optical elements," Phys. Rev. Lett. 96, 153902 (2006).

[Crossref]
[PubMed]

V. Dudiy and A. Zunger, "Searching for alloy configurations with target physical properties: impurity design via a genetic algorithm inverse band structure approach," Phys. Rev. Lett. 97, 046401 (2006).

[Crossref]
[PubMed]

V. G. Veselago, "The electrodynamics of substances with simultaneously negative values of epsi and μ," Sov. Phys. Usp. 10, 509-514 (1968).

[Crossref]

R. P. Brent, Algorithms for Minimization Without Derivatives (Dover, 2002).