Aspects of the present disclosure describe integrated-optics-based phase controllers comprising waveguides whose cores have one or more cavities, thereby enabling them to exhibit an enhanced photo-elastic effect and/or increased stress-induced deformation in at least one region. Waveguides in accordance with the present disclosure are particularly well suited for use in stress-optic phase controllers suitable for use in systems such as microwave photonics, LIDAR and the like.

Various embodiments include large cores fibers that can propagate few modes or a single mode while introducing loss to higher order modes. Some of these fibers are holey fibers that comprise cladding features such as air-holes. Additional embodiments described herein include holey rods. The rods and fibers may be used in many optical systems including optical amplification systems, lasers, short pulse generators, Q-switched lasers, etc. and may be used for example for micromachining.

Disclosed is a small-diameter polarization maintaining optical fiber, which relates to the field of special optical fibers. The small-diameter polarization maintaining optical fiber comprises a quartz optical fiber (5); the periphery thereof is provided with an inner coating (6) and an outer coating (8); the interior of the quartz optical fiber (5) is provided with an optical fiber core layer (1) and a quartz cladding (2); two stress zones (4) are arranged between the optical fiber core layer (1) and the quartz cladding (2); a buffer coating (7) is arranged between the inner coating (6) and the outer coating (8); the periphery of each stress zone (4) is provided with a buffer layer (3) which is concentric with the stress zone (4); when a working wavelength of a small-diameter polarization maintaining optical fiber is 1310 nm, the attenuation thereof reaches less than 0.5 dB/km, and the crosstalk reaches 35 dB/km; and when the working wavelength of the small-diameter polarization maintaining optical fiber is 1550 nm, the attenuation thereof reaches less than 0.4 dB/km, and the crosstalk reaches 30 dB/km. The optical fiber not only has excellent stability characteristics of attenuation and crosstalk, but also has the excellent stability characteristic of long-term operation, and can provide a better optical fiber ring for research on a high-precision optical fiber gyroscope, thereby laying the foundation for the development directions of miniaturization and high precision of the optical fiber gyroscope.

An optical fiber fixing structure includes: a cylindrical member; an optical fiber inserted into a hole of the cylindrical member; and a fixing material configured to fix the cylindrical member and the optical fiber, wherein the optical fiber is a polarization maintaining optical fiber having a polarization axis, and a center of the optical fiber is arranged so as to be eccentric to a center of the hole, and an angle formed by an eccentric direction connecting the center of the hole and the center of the optical fiber and the polarization axis is 22.5 to 22.5, or 67.5 to 112.5.

A communication apparatus includes an optical fiber along which radiation can be transmitted; an optical fiber grating formed within the optical fiber, the optical fiber grating having a structure, and configured to reflect radiation at a particular wavelength; and an instrument coupled to the grating and configured to controllably modify the structure of the grating, thereby changing the wavelength at which the grating reflects radiation. A communication system including the communication apparatus is also described, along with a method of communicating a signal.

The invention relates to a method for producing a polarization-maintaining optical fibre, consisting of a core region and stress-generating elements embedded in the fibre body, having the following method steps: producing a core preform for the core region using internal deposition on a substrate tube, the internally coated substrate tube subsequently being collapsed, generating recesses on the core preform by virtue of the material on the outer surface of the core preform being removed parallel to the longitudinal axis of the core preform at diametrically opposed positions, filling the recesses with stress-generating rods, with the tightest possible rod packing, in a freely selectable first filling geometry, possibly filling the recesses in addition with non-stress-generating rods in a second filling geometry, sheathing the filled core preform with a jacketing tube, preparing the sheathed core preform for a fibre-drawing process, and drawing the sheathed arrangement to form in the optical fibre. A preform for producing a polarization-maintaining optical fibre contains a core preform, having a core region and a lateral region, and also contains a jacketing tube, which encloses the core preform, as well as stress-generating elements contained in the lateral region, wherein the stress-generating elements are provided in the form of recesses in the lateral region, wherein the recesses are filled with doped rods and/or undoped rods, and wherein the rod filling forms a first and/or a second arrangement geometry.

The present Specification is directed to devices for controlling the phase of a light signal in a surface waveguide of a planar-lightwave circuit by controlling a stress in the waveguide material. Phase controllers disclosed can impart stresses of opposite signs in a material such that a desired effect on the refractive index of an optical material can be accentuated. As a result, a greater change in the refractive index of the material can be realized in a phase controller that requires less chip real estate and/or at lower voltages. In some embodiments, a phase-control module includes a pair of complimentary stress-optic phase controllers, one having electrodes disposed on the top and bottom of a piezoelectric layer, while the other has electrodes disposed only on top of the piezoelectric layer. As a result, the phase controllers impart stress of opposite sign in the material beneath them.

A control system performs a method of controlling a wing of an airplane. The control system includes an optical fiber, a bending device and a processor. The optical fiber is configured to receive light having an input optical phase. The bending device applies an external force on the optical fiber. The external force causes the light exiting the optical fiber to have an output optical phase. a processor determines a phase shift between the input optical phase and the output optical phase and controls the wing based on the phase shift.

Embodiments herein describe using an actuator to tune a waveguide. In one embodiment, the tunable waveguide includes a gap between the waveguide and cladding. The actuator can compress the cladding to shrink this air, bringing the cladding closer to the waveguide. Doing so changes the effective refractive index of the waveguide. Alternatively or additionally, the actuator can increase the gap.

Techniques for creating an SiGe/Si electro-optomechanical quantum transducer, comprising an SiGe/Si optical ring resonator and capacitor, that can be associated with a qubit are presented. The optical resonator, comprising an SiGe optical waveguide and a strained silicon membrane, can be formed and disposed over a substrate. The strained silicon membrane can have a photoelastic coupling with the SiGe optical waveguide. A capacitor, comprising a superconducting material, can be formed in proximity to the optical resonator. The top plate of the capacitor can be associated with the strained silicon membrane. A recessed region can be formed in the back side of the substrate along a desired silicon plane, extending to form a hole in the top side of the substrate. A superconducting material can be applied along substrate surfaces defining the recessed region and hole. The superconducting material covering the hole can be the bottom plate of the capacitor.