High omnidirectional reflector

A high omnidirectional reflector which exhibits reflection for a predetermined range of frequencies of incident electromagnetic energy for any angle of incidence and any polarization, comprising:

• a structure with a surface and a refractive index variation along the direction perpendicular to said surface while remaining nearly uniform along the surface, said structure configured such that,
• i) a range of frequencies exists defining a photonic band gap for electromagnetic energy incident along the perpendicular direction of said surface,
• ii) a range of frequencies exists defining a photonic band gap for electromagnetic energy incident along a direction approximately 90.degree. from the perpendicular direction of said surface, and
• iii) a range of frequencies exists which is common to both of said photonic band gaps.

A method of creating high omnidirectional reflection for a predetermined range of frequencies of incident electromagnetic energy for any angle of incidence and any polarization, comprising:

• providing a structure with a surface and a refractive index variation along the direction perpendicular to said surface while remaining nearly uniform along the surface, said structure configured such that
• i) a range of frequencies exists defining a photonic band gap for electromagnetic energy incident along the perpendicular direction of said surface,
• ii) a range of frequencies exists defining a photonic band gap for electromagnetic energy incident along a direction approximately 90.degree. from the perpendicular direction of said surface, and
• iii) a range of frequencies exists which is common to both of said photonic band gaps.

A method for producing an all dielectric omnidirectional reflector which exhibits oenidirectional reflection that is greater than 95% for a predetermined range of frequencies of incident electromagnetic energy of any angle of incidence and any polarization comprising:

• providing a structure with a surface and a refractive index variation along the direction perpendicular to the said surface while remaining nearly uniform along the surface, said surface configured such that
• (i) a range of frequencies exists defining a reflectivity range which is higher than 99% for electromagnetic energy incident along the perpendicular direction of the said surface,
• (ii) a range of frequencies exists defining a reflectivity range which is higher than 99% for electromagnetic energy incident a direction approximately 90.degree. from the perpendicular direction of the said surface, and
• (iii) a range of frequencies exists which is common to both of said reflectivity ranges.