A method of fabricating an acousto-optic waveguide that includes a waveguide cladding surrounding an optical core is disclosed. The method comprises providing a wafer substrate; depositing an initial amount of a first material over an upper surface of the wafer substrate to form a partial cladding layer; depositing a second material over the partial cladding layer to form an optical layer; removing portions of the second material of the optical layer to expose portions of the partial cladding layer and form an optical core comprising the remaining second material; and depositing an additional amount of the first material over the optical core and the exposed portions of the partial cladding layer to form a full cladding layer that surrounds the optical core. A relative concentration of components of the first material is adjusted to provide Brillouin gain spectral position control of the waveguide cladding to tune the acousto-optic waveguide.

An acousto-optic waveguide device comprises a substrate comprising a first material having a first refractive index and a first acoustic velocity; a cladding layer over the substrate, the cladding layer comprising a second material having a second refractive index that is distinct from the first refractive index, the second material having a second acoustic velocity that is distinct from the first acoustic velocity; and an optical core surrounded by the cladding layer, the optical core comprising a third material having a third refractive index that is higher that the first refractive index and the second refractive index, the third material having a third acoustic velocity that is distinct from the first acoustic velocity and the second acoustic velocity. The cladding layer that surrounds the optical core has a thickness configured to substantially confine acoustic waves to the cladding layer when an optical signal propagates through the optical core.

An acousto-optic waveguide device comprises a substrate comprising a first material having a first refractive index and a first acoustic velocity; a cladding layer over the substrate, the cladding layer comprising a second material having a second refractive index that is distinct from the first refractive index, the second material having a second acoustic velocity that is distinct from the first acoustic velocity; and an optical core surrounded by the cladding layer, the optical core comprising a third material having a third refractive index that is higher that the first refractive index and the second refractive index, the third material having a third acoustic velocity that is distinct from the first acoustic velocity and the second acoustic velocity. The cladding layer that surrounds the optical core has a thickness configured to substantially confine acoustic waves to the cladding layer when an optical signal propagates through the optical core.

An apparatus (32) includes an electronic circuit (76, 80, 84), an electro-acoustic transducer (60) and a coupler (64). The electronic circuit is configured to receive data to be transmitted over an optical cable (24), and to convert the data into a modulating signal. The electro-acoustic transducer is configured to convert the modulating signal into an acoustic wave. The coupler is mechanically coupled to a section of the optical cable, and is configured to apply to the section a longitudinal strain that varies responsively to the acoustic wave, so as to modulate the data onto an optical carrier traversing the optical cable.

An apparatus (32) includes an electronic circuit (76, 80, 84), an electro-acoustic transducer (60) and a coupler (64). The electronic circuit is configured to receive data to be transmitted over an optical cable (24), and to convert the data into a modulating signal. The electro-acoustic transducer is configured to convert the modulating signal into an acoustic wave. The coupler is mechanically coupled to a section of the optical cable, and is configured to apply to the section a longitudinal strain that varies responsively to the acoustic wave, so as to modulate the data onto an optical carrier traversing the optical cable.

An illuminating device includes an illumination light generator configured to generate illumination pulses of coherent light, and a speckle modulator configured to modulate speckle caused by the coherent light. The illumination pulse generator repeatedly generates a single illumination pulse group including a plurality of illumination pulses as a repetitive illumination pulse group.

An illuminating device includes an illumination light generator configured to generate illumination pulses of coherent light, and a speckle modulator configured to modulate speckle caused by the coherent light. The illumination pulse generator repeatedly generates a single illumination pulse group including a plurality of illumination pulses as a repetitive illumination pulse group.

A light source assembly having N outputs is disclosed. The assembly comprising: a light source arrangement arranged for supplying light to M inputs, where M an N independently of each other are integers and where M2 and MN; at least one optical couplers, each having at least one input arm and a plurality of output arms; and an integer number, P, of mode scramblers;

The light source arrangement may comprise a broadband light source and a multimode coupler configured for receiving one or more light beams from the light source arrangement, wherein the one or more light beams being derived from the broadband light source and wherein a mode scrambler is arranged for mode scrambling one of said light beams before it enters the multimode coupler.

A light source assembly having N outputs is disclosed. The assembly comprising: a light source arrangement arranged for supplying light to M inputs, where M an N independently of each other are integers and where M2 and MN; at least one optical couplers, each having at least one input arm and a plurality of output arms; and an integer number, P, of mode scramblers;

The light source arrangement may comprise a broadband light source and a multimode coupler configured for receiving one or more light beams from the light source arrangement, wherein the one or more light beams being derived from the broadband light source and wherein a mode scrambler is arranged for mode scrambling one of said light beams before it enters the multimode coupler.

A fiber optic cable assembly includes an elongate housing, a signal fiber placed inside the housing and extending longitudinally, and a plurality of sensing fibers placed inside the housing and extending longitudinally. The plurality of sensing fibers is placed around the signal fiber. Each of the plurality of sensing fibers carries a respective laser signal of a distinct frequency. The signal fiber carries one or more evanescent coupling signals responsive to the laser signals in the plurality of sensing fibers.