Described herein are technologies related to passive or active cloaking devices. More particularly, the passive or active cloaking devices utilize input/output grating couplers and waveguides to create an impression of invisibility on an object that is covered by the passive or active cloaking devices.

A system and method for delivering stable light to a remote location are provided. The method includes splitting a laser beam generated by a laser into a reference beam and a delivery beam. The delivery beam is coupled into an optical fiber for delivery to the remote location. A reflected portion of the delivery beam comes back as a reflected delivery beam from the remote location through the optical fiber. An interference beam is generated by combining the reference beam and the reflected delivery beam. A phase difference between the reference beam and the reflected delivery beam is detected in order to adjust a phase of the laser beam based on the phase difference to reverse a phase shift of the delivery beam induced by noise added to the delivery beam while the delivery beam is transmitted through the optical fiber.

A three-dimensional Bragg grating may include a single colloidal crystal that includes a plurality of repeated layers of material having different refractive indexes. A sample cell for producing a volume Bragg grating may include an internal shape that forms at least one capillary cell having a flat surface and rounded edges. A method of producing a three-dimensional Bragg grating may include: suspending insoluble particles in a host fluid to form a suspension; and exposing the suspension to a sustained microgravity environment.

Apparatuses relate generally to a fiber optic cable. In such an apparatus, a housing has a channel or bore for receipt of a portion of the fiber optic cable having a fiber optic sensor. An acoustic interface layer is coupled to a surface of the housing to reduce stress wave coupling loss at an interface between the fiber optic sensor and a host structure surface. In another such apparatus, a patch structure is for a fiber optic cable coupled to a fiber optic voltage conditioner. In yet another such apparatus, a fiber optic voltage conditioner is coupled for optical communication to a fiber optic cable having a Fiber Bragg Grating sensor. The fiber optic voltage conditioner includes a tunable light source having a broadband light source or a gain medium configured to provide a narrowband light signal from a broadband light signal for providing to the fiber optic cable.

A gauge carrier holds an optical fiber having a gauge portion provided in one axial part thereof. A center region has a predefined stiffness and holds the gauge portion. Length in the longitudinal direction of the gauge carrier is equal to or greater than length of the gauge portion. Two split regions each have a stiffness different from that of the center portion, total length of the split regions in the longitudinal direction of the gauge carrier is greater than the length of the center region in the longitudinal direction, one of the split regions is positioned in front of the center region and holds a part of the optical fiber that is in front of the gauge portion, and the other is positioned in back of the center region and holds a part of the optical fiber that is in the back of the gauge portion.

Apparatuses relate generally to a fiber optic cable. In such an apparatus, a housing has a channel or bore for receipt of a portion of the fiber optic cable having a fiber optic sensor. An acoustic interface layer is coupled to a surface of the housing to reduce stress wave coupling loss at an interface between the fiber optic sensor and a host structure surface. In another such apparatus, a patch structure is for a fiber optic cable coupled to a fiber optic voltage conditioner. In yet another such apparatus, a fiber optic voltage conditioner is coupled for optical communication to a fiber optic cable having a Fiber Bragg Grating sensor. The fiber optic voltage conditioner includes a tunable light source having a broadband light source or a gain medium configured to provide a narrowband light signal from a broadband light signal for providing to the fiber optic cable.

Described herein are technologies related to passive or active cloaking devices. More particularly, the passive or active cloaking devices utilize input/output grating couplers and waveguides to create an impression of invisibility on an object that is covered by the passive or active cloaking devices.

A system and method for delivering stable light to a remote location are provided. The method includes splitting a laser beam generated by a laser into a reference beam and a delivery beam. The delivery beam is coupled into an optical fiber for delivery to the remote location. A reflected portion of the delivery beam comes back as a reflected delivery beam from the remote location through the optical fiber. An interference beam is generated by combining the reference beam and the reflected delivery beam. A phase difference between the reference beam and the reflected delivery beam is detected in order to adjust a phase of the laser beam based on the phase difference to reverse a phase shift of the delivery beam induced by noise added to the delivery beam while the delivery beam is transmitted through the optical fiber.

A three-dimensional Bragg grating may include a single colloidal crystal that includes a plurality of repeated layers of material having different refractive indexes. A sample cell for producing a volume Bragg grating may include an internal shape that forms at least one capillary cell having a flat surface and rounded edges. A method of producing a three-dimensional Bragg grating may include: suspending insoluble particles in a host fluid to form a suspension; and exposing the suspension to a sustained microgravity environment.