US 4,363,533 A · Concentric fiber optical transducer

Abstract

An optical transducer (10) having a plurality of concentric cores (15,17). An intermediate cladding (16) is disposed between the inner and outer cores and an outer cladding (18) surrounds the outer core to define a symmetrical cylindrical transducer structure. Light propagated through the inner core (15) from a source (19) is coupled into the outer core (17) as a result of penetration of the evanescent electric field from the light in the inner core through the inner cladding (16) to the outer core. Control of the coupling length may be effected by suitable selection of the transducer structure parameters. At least one of the portions of the transducer is formed of an acousto-optically variable material whereby an acoustic field acting on the transducer causes a modulation of the coupled light so as to provide in the outer core (17) a modulated light signal suitable for detection by a receiver (21). Localized control of the parameters of the transducer may be effected to provide focusing of the coupled light. An electrical signal may be provided for controlling the coupling between the core portions.

Claims25

Dependent claims

An optical transducer comprising:

an inner optical cylindrical fiber core;
an inner optical cladding concentrically disposed about said core formed of a material having a refractive index less than that of said inner core;
an outer optical core concentrically disposed about said inner cladding formed of a material having a refractive index greater than the refractive index of said inner cladding;
and
an outer optical cladding concentrically disposed about said outer core formed of a material having a refractive index less than that of said outer core, the materials comprising at least one of said core and cladding elements being differently optically responsive to cause a variation in the difference between the refractive indices of said elements as a result of an acoustic vibratory force acting on said transducer, said refractive indices and the configuration of the concentric cores and claddings being preselected to define means for effecting transfer of energy from one core to the other through variations in the extension of the evanescent electric field of the light propagated in said inner core outwardly through said inner cladding into said outer core.

2 more elements

An optical transducer comprising:

an inner optical fiber core;
an inner optical cladding concentrically disposed about said core formed of a material having a refractive index less than that of said inner core;
an outer optical core concentrically disposed about said inner cladding formed of a material having a refractive index greater than the refractive index of said inner cladding;
and
an outer optical cladding concentrically disposed about said outer core formed of a material having a refractive index less than that of said outer core, the material comprising said inner cladding having a variable dielectric constant for the frequency of light to be propagated through said inner fiber core to cause a variation in the evanescent coupling of light from said inner fiber core to said outer core as a result of a physical effect acting on said transducer, said refractive indices and the configuration of the concentric cores and claddings being preselected to define means for effecting transfer of energy from one core to the other through variations in the extension of the evanescent electric field of the light propagated in said inner core outwardly through said inner cladding into said outer core, the arrangement of the transducer portions defining focusing means for focusing light carried in a portion of said outer core for facilitated transfer therefrom, the arrangement including an asymmetrical construction of at least one of said concentric portions.

2 more elements

Dependencies are inferred from the claim text.

Concentric fiber optical transducer

Life of this patent

Concentric fiber optical transducer

Life of this patent

Abstract

Claims25