Systems and methods of dispersion compensation in an optical device are disclosed. A holographic optical element may include a set of different holograms in a grating medium. Each hologram in the set may have a corresponding grating vector with a grating frequency and direction. The directions of the grating vectors may vary as a function of the grating frequency. Different holograms in the set may diffract light in a particular direction so that the light emerges from a boundary of the grating medium in a single given direction regardless of wavelength. A prism may be used to couple light into the grating medium. The prism may be formed using materials having dispersion properties that are similar to the dispersion properties of the grating material. The prism may have an input face that receives perpendicular input light. The prism may include multiple portions having different refractive indices.

Coated optical fibers and uses of such fibers as sensors in high temperature and/or high pressure environments. The coated optical fiber has improved sensing properties at elevated pressure and/or temperature, such as enhanced acoustic sensitivity and/or a reduced loss in acoustic sensitivity. The use of the coated optical fibers in various sensing applications that require operation under elevated pressure and/or temperature, such as, acoustic sensors for various geological, security, military, aerospace, marine, and oil and gas applications are also provided.

A light emitting element array includes plural light emitting elements connected in parallel to each other by a wiring connected to a terminal that supplies a current. Each of the light emitting elements is disposed at a position of a predetermined path length along a path of the current flowing from the terminal through the wiring. The plural light emitting elements include, in a mixed form, one or more first light emitting elements each having a non-shielded light emission aperture and one or more second light emitting elements each having a shielded light emission aperture. At least one of the first light emitting elements is disposed at a position of the longest path length. At least one of the second light emitting elements is disposed at a position of the shortest path length.

Provided is a cladded single crystal sapphire optical fiber. In one embodiment, the innovation provides a method for forming a cladding in a single crystal sapphire optical fiber by reactor irradiation. The reactor irradiation creates ions external to the fiber that enter the fiber, displace atoms in the fiber, and are implanted in the fiber, thus modifying the index of refraction of the fiber near the surface of the fiber and creating a cladding in the sapphire fiber.

A photonic displacement sensor comprises a photonic fiber including a) a core section having a first band gap aligned along an extended longitudinal axis, and b) a cladding section surrounding the core section having a second band gap. The first band gap is adapted to block a spectral band of radiation centered on a first wavelength that is directed along the longitudinal axis, and the second band gap is adapted to block a spectral band of radiation centered on a second wavelength that is directed transversely to the longitudinal axis, and wherein displacement is detected based on a shift in at least one of the first and second band gap of the photonic fiber, enabling an intensity of radiation to be detected that is in proportion to the displacement in the photonic fiber.

A phase controller for controlling the phase of a light signal in a surface waveguide and a method for its fabrication are disclosed. The phase controller controls the phase of the light signal by inducing stress in the waveguide structure, thereby controlling the refractive indices of at least some of its constituent layers. The phase controller includes a phase-control element formed on topographic features of the top cladding of the waveguide, where these features (1) provide a shape to the phase-control element that matches the shape of the mode field of the light signal and (2) give rise to stress-concentration points that focus and direct induced stress into specific regions of the waveguide structure, thereby providing highly efficient phase control. As a result, the phase controller can operate at a lower voltage, lower power, and/or over a shorter interaction length than integrated-optic phase controllers of the prior art.

A method for estimating an environmental parameter includes transmitting a first interrogation signal into an optical fiber, receiving a reflected return signal including light reflected from one or more of the plurality of FBG's in the fiber and receiving at a processor data describing the reflected return signal. The received data is comparted to expected data to determine a shift in wavelength of light reflected for one or more of the plurality of FBGs and a change in a length of a dead zone of the optical fiber based on the comparison is also determined. From this, estimates of locations two or more of the plurality of FBG's are formed.

Improvements to gratings for use in waveguides and methods of producing them are described herein. Deep surface relief gratings (SRGs) may offer many advantages over conventional SRGs and Bragg gratings, an important one being a higher S-diffraction efficiency. In one embodiment, deep SRGs can be implemented as polymer surface relief gratings or evacuated Bragg gratings (EBGs). EBGs can be formed by first recording a holographic polymer dispersed liquid crystal (HPDLC) grating. Removing the liquid crystal from the cured grating provides a polymer surface relief grating. Polymer surface relief gratings have many applications including for use in waveguide-based displays.

A fiber optic light source in which input light with short and narrow band wavelength is converted/transformed into multi-band visible white light with high intensity output power is provided. The new light source comprises at least one homogenizing light guide element, and at least one photoluminescence element. It may also comprise at least one input element and an optical fiber. All or some of the elements may be integrated into an optical waveguide. In some embodiments, the at least one input element increases light transfer efficiency from a ray source to the at least one homogenizing light guide element component of the fiber optic light source. The at least one photoluminescence element can be a point or an extended form like a line or surface. The fiber optic light source output beam may also contain the input ray wavelength, which in turn can be from a fiber optic laser. In operation, an input ray travels through at least one homogenizing light guide element and irradiates at least one photoluminescence element present in preselected positions of the device to cause large area or spacious illumination at a desired target. This source can be an information source to communicate information through light modulation not noticeable to the naked human eye. Information is sent from the optical light source to information receivers, technical devices like smart phones, TV-Displays, or other devices, which could replace the common use of LAN or WLAN networks. Here a known luminescent detector can be used to efficiently collect the information in its optical form and to lead it to a suitable photo detector. This enables free-space optical light information transfer especially in areas where traditional infrastructure using transmitting fibers is difficult to establish.

The ends of sensing and interrogating multicore fibers are brought into proximity for connection in a first orientation with one or more cores in the sensing fiber being paired up with corresponding one or more cores in the interrogating fiber. Optical interferometry is used to interrogate at least one core pair and to determine a first reflection value that represents a degree of alignment for the core pair in the first orientation. The relative position is adjusted between the ends of the fibers to a second orientation. Interferometry is used to interrogate the core pair and determine a second reflection value that represents a degree of alignment for the core pair in the second orientation. The first reflection value is compared with the second reflection value, and an aligned orientation is identified for connecting the sensing and interrogating fibers based on the comparison.