Two demensional distributed feedback devices and lasers

Claim 2

A thin film optical device comprising an optical waveguide having boundary surfaces and defining a guided wavelength for propagating wave of light at a predetermined frequency and guided wavelength therein, said waveguide having a predetermined optical index of refraction and made of a material transparent to light of said predetermined frequency, means defining at least one boundary layer adjacent to said waveguide such that the propagating wave for light at said predetermined frequency extends botH within said waveguide and into said boundary layer, said boundary layer having one or more indices of refraction of said waveguide, perturbation means associated with said boundary layer and said waveguide for forming a first periodic variation of the index of refraction thereof in a first predetermined direction, said first periodic variation causing a spatial variation of said index of refraction between two values which repeat in a regular pattern of a first predetermined periodicity ay, said perturbation means further forming a second periodic variation of said index of refraction in a second predetermined direction and causing a spatial variation of said second periodic variation between two values which repeat in regular patern of a second predetermined periodicity az.

Claim 3

A thin film optical device as in claim 1 in which said means forming said periodic variations comprises a two dimensional array of scattering centers.

Claim 4

A thin film optical device as in claim 2 in which said perturbation means includes a first array of reflective linear elements forming a first grating and a second array of reflective linear elements forming a second grating.

Claim 5

A thin film optical device as in claim 1 in which said first and second periodic variations are orthogonal to each other.

Claim 6

A thin film optical device as in claim 1 in which said first and second periodic variations are oblique to each other.

Claim 7

A thin film optical device as in claim 1 wherein periodicities ay and az satisfy the relation

Claim 8

A thin film optical device comprising an optical waveguide having boundary surfaces and defining a guided wavelength for propagating wave of light at a predetermined frequency, said waveguide having a predetermined optical index of refraction and made of a material transparent to light of said predetermined frequency, means defining one or more boundary layer adjacent to said waveguide such that the propagating wave for light at said predetermined frequency extends both within said waveguide and into said boundary layer, said boundary layer or layers having one or more indices of refraction at least a portion of which is less than the index of refraction of said waveguide, first perturbation means associated with said boundary layer, said waveguide or the interface between said boundary layer and said waveguide for forming a periodic variation of the index of refraction thereof in a first predetermined direction, said periodic variation being arranged for causing a spatial variation of said index of refraction between two values which repeat in a regular pattern in a predetermined periodicity ay, second perturbation means associated with one of said boundary layers and waveguide or the interface of said boundary layer and said waveguide for forming a periodic variation of the index of refraction thereof in a second predetermined direction, said second periodic variation being arranged for causing spatial variation of said index of refraction between two values which repeat in regular pattern of a second predetermined periodicity az wherein

Claim 9

A thin film optical device comprising an optical waveguide having boundary surfaces and defining a guided wavelength for propagating wave of light at a predetermined frequency, said waveguide having a predetermined optical index of refraction and made of a material transparent to light of said predetermined frequency, means defining one or more boundary layer adjacent to said waveguide such that the propagating wave for light at said predetermined frequency extends both within said waveguide and into said boundary layer, said boundary layer or layers having one or more indices of refraction at least a portion of which is less than the index of refraction of said waveguide, first perturbation means associated with said boundary layer, said waveguide or the interface between said boundary layer and said waveguide for forming a periodic variation of the index of refraction thereof in a first predetermined direction, said periodic variation being arranged for causing a spatial variation of said index of refraction between two values which repeat in a regular pattern in a predetermined periodicity ay, second perturbation means associated with one of said boundary layers and waveguide or the interface of said boundary layer and said waveguide for forming a periodic variation of the index of refraction thereof in a second predetermined direction, said second periodic variation being arranged for causing spatial variation of said index of refraction between two values which repeat in regular pattern of a second predetermined periodicity az wherein

Claim 10

A device in claim 7 further including generator means for applying an acoustic field to said boundary layer and means for varying the frequency of the output of said generator.

Claim 11

A device as in claim 7 further including an ultrasonic generator coupled to said boundary layer and means for varying the frequency output of said generator.

Claim 12

A device as in claim 7 wherein said boundary layer has an index of refraction variable in response to an applied electric field and further including means for applying an electric field to said layer, means for varying the strength of said field.

Claim 13

A device as in claim 7 wherein said boundary layer has an index of refraction variable in response to an applied magnetic field and further including means for applying a magnetic field to said layer, means for varying the strength of said field.

Claim 14

A device as in claim 7 wherein said boundary layer has an index of refraction variable in response to an applied acoustic standing wave pattern, and further including means for extablishing an acoustic standing wave pattern in said layer.

Claim 15

A thin film optical device comprising an optical waveguide having boundary surfaces and defining a guided wavelength for propagating wave of light at a predetermined frequency, said waveguide having a predetermined optical index of refraction and made of a material transparent to light of said predetermined frequency, means defining at least one boundary layer adjacent to said wave-guide and in such proximity that the propagating wave for light at said predetermined frequency extends both within said waveguide and into said boundary layer, said boundary layer having one or more indices of refraction at least a portion of which is less than the index of refraction of said waveguide, perturbation means associated with said boundary layer, said waveguide or the interface between said boundary layer and said waveguide for forming a first periodic variation of the index of refraction thereof in a first predetermined direction, said periodic variation being arranged for causing a spatial variation of said index of refraction between two values which repeat in a regular pattern of at least one first predetermined periodicity ay, said perturbation means further forming a second periodic variation of the index of refraction thereof in a second predetermined direction different from said first direction, said second periodic variation varying between two values which repeat in regular pattern of at least one second predetermined periodicity az.

Claim 16

A thin film optical device comprising an optical waveguide having boundary surfaces and defining a guided wavelength for propagating wave of light at a predetermined frequency, said waveguide having a predetermined optical index of refraction and made of a material transparent to light of said predetermined frequency, means defining at least one boundary layer adjacent to said wave-guide and in such proximity that the propagating wave for light at said predetermined frequency extends both within said waveguide and into said boundary layer, said boundary layer having one or more indices of refraction at least a portion of which is less than the index of refraction of said waveguide, perturbation means associated with said boundary layer, said waveguide or the interface between said boundary layer and said waveguide for forming a first periodic variation of the index of refraction thereof in a first predetermined direction, said periodic variation being arranged for causing a spatial variation of said index of refraction between two values which repeat in a regular pattern of at least one first predetermined periodicity ay, said perturbation means further forming a second periodic variation of the index of refraction thereof in a second predetermined direction different from said first direction, said second periodic variation varying between two values which repeat in regular pattern of at least one second predetermined periodicity az.

Claim 17

A thin film optical device as in claim 13 wherein said first and second periodic variations are scattering centers located at the intersections of a pair of crossed-gratings.