Abstract: Method of synthesis of photonic band gap (PBG) materials. The synthesis and characterization of high quality, very large scale, face centered cubic photonic band gap (PBG) materials consisting of pure silicon, exhibiting a complete three dimensional PBG centered on a wavelength of 1.5 ?m. This is obtained by chemical vapor deposition and anchoring of disilane into a self-assembling silica opal template, wetting of a thick silicon layer on the interior surfaces of the template, and subsequent removal of the template. This achievement realizes a long standing goal in photonic materials and opens a new door for complete control of radiative emission from atoms and molecules, light localization and the integration of micron scale photonic devices into a three-dimensional all-optical micro-chip.

Abstract: Method of synthesis of photonic band gap (PBG) materials. The synthesis and characterization of high quality, very large scale, face centered cubic photonic band gap (PBG) materials consisting of pure silicon, exhibiting a complete three dimensional PBG centered on a wavelength of 1.5 ?m. This is obtained by chemical vapor deposition and anchoring of disilane into a self-assembling silica opal template, wetting of a thick silicon layer on the interior surfaces of the template, and subsequent removal of the template. This achievement realizes a long standing goal in photonic materials and opens a new door for complete control of radiative emission from atoms and molecules, light localization and the integration of micron scale photonic devices into a three-dimensional all-optical micro-chip.

Abstract: The present invention provides fully tunable photonic band gap (PBG) materials. These materials are periodic composite materials comprising a high refractive index dielectric material and another optically anisotropic, birefringent, electro-optically tunable, or magneto-optically tunable material with a lower dielectric constant in which the photonic band structure can be globally or locally changed in a controlled manner by application of an external electric, magnetic, or electromagnetic field, whereby changing the refractive index properties of one or more of the dielectric constituents by application of the field modulates the photonic band structure. In one aspect of the invention, when an optically birefringent nematic liquid crystal is infiltrated into the void regions of full bandgap (PBG) material based on an inverse opal, the resulting composite material exhibits a completely tunable PBG.

Abstract: An instrument for measuring reliably and instantaneously the chemical quality of cooking oil, and for distinguishing between color changes due to chemical changes and color changes due to the presence of minute size food particles in various oils.

Abstract: Method of synthesis of photonic band gap (PBG) materials. The synthesis and characterization of high quality, very large scale, face centered cubic photonic band gap (PBG) materials consisting of pure silicon, exhibiting a complete three-dimensional PBG centered on a wavelength of 1.5 &mgr;m. This is obtained by chemical vapor deposition and anchoring of disilane into a self-assembling silica opal template, wetting of a thick silicon layer on the interior surfaces of the template, and subsequent removal of the template. This achievement realizes a long standing goal in photonic materials and opens a new door for complete control of radiative emission from atoms and molecules, light localization and the integration of micron scale photonic devices into a three-dimensional all-optical micro-chip.

Abstract: An instrument for measuring reliably and instantaneously the chemical quality of cooking oil, and for distinguishing between colour changes due to chemical changes and colour changes due to the presence of minute size food particles in various oils.

Abstract: The present invention relates to photonic band gap (PBG) materials and more specifically, it describes a new type of photonic crystal structure which exhibits a large and complete three-dimensional PBG. This PBG is highly robust to the effects of disorder. The photonic crystal has a tetragonal or hexagonal lattice symmetry and is comprised of a lattice of polygonal spiral posts of a high refractive Index material in a low index background. The corresponding inverse structure comprises a lattice of low refractive index posts in a high refractive index background also has a very large PBG. These new photonic crystals exhibit very large (up to 23.6% when made of silicon and nearly 29% when made of germanium) complete 3D photonic band gaps. The posts exhibit a spiral profile and all the spiral posts wind in phase with each other. The identity of the winding phase from one post to the next makes the present invention amenable to micro-fabrcation using the Glancing Angle Deposition (GLAD).

Abstract: The present invention provides fully tunable photonic band gap (PBG) materials. These materials are periodic composite materials comprising a high refractive index dielectric material and another optically anisotropic, birefringent, electro-optically tunable, or magneto-optically tunable material with a lower dielectric constant in which the photonic band structure can be globally or locally changed in a controlled manner by application of an external electric, magnetic, or electromagnetic field, whereby changing the refractive index properties of one or more of the dielectric constituents by application of the field modulates the photonic band structure. In one aspect of the invention, when an optically birefringent nematic liquid crystal is infiltrated into the void regions of full bandgap (PBG) material based on an inverse opal, the resulting composite material exhibits a completely tunable PBG.

Abstract: The present invention relates to photonic band gap (PBG) materials and more specifically, it describes a new type of photonic crystal structure which exhibits a large and complete three-dimensional PBG. This PBG is highly robust to the effects of disorder. The photonic crystal has a tetragonal or hexagonal lattice symmetry and is comprised of a lattice of polygonal spiral posts of a high refractive index material in a low index background, The corresponding inverse structure comprises a lattice of low refractive index posts in a high refractive index background also has a very large PBG. These new photonic crystals exhibit very large (up to 23.6% when made of silicon and nearly 29% when made of germanium) complete 3D photonic band gaps. The posts exhibit a spiral profile and all the spiral posts wind in phase with each other. The identity of the winding phase from one post to the next makes the present invention amenable to micro-fabrication using the Glancing Angle Deposition (GLAD).