Abstract:
An optically active linear single polarization device includes a linearly birefringent and linearly dichroic optical waveguide (30) for propagating light and having single polarization wavelength range (48). A plurality of active dopants are disposed in a portion (34) of the linearly birefringent and linearly dichroic optical waveguide (30) for providing operation of the waveguide in an operating wavelength range (650) for overlapping the single polarization wavelength range (48).
Abstract:
A method is described for reducing the effect of linear birefringence in an optical fiber, in particular a circular-cored single-mode fiber. The invention may also be directed to an optical fiber having a reduced linear birefringence. A length of the optical fiber may be subdivided into a plurality of sections and a twist having a predetermined sense of rotation and a twist angle may be introduced between the sections. Fibers of this type may find applications, for example, in fiber-optic current and magnetic field sensors.
Abstract:
A birefringent elongate waveguide for guiding light, comprises: a core region (110), comprising an elongate region of relatively low refractive index; and a cladding region (100), comprising elongate regions (105) of relatively low refractive index interspersed with elongate regions (117,120) of relatively high refractive index. In a transverse cross-section of the waveguide, a (5) relatively high refractive index boundary region (115) is provided that surrounds the core region and has either (1) at most two-fold rotational symmetry or (2) a rotational symmetry that reduces the rotational symmetry of the waveguide to at most two-fold rotational symmetry. The symmetry of the boundary region (115) results at least in part from azimuthal variations therein, which are substantially uncharacteristic of the cladding region (100).
Abstract:
An optical fiber includes a substantially transparent core that carries a light signal, a substantially transparent cladding surrounding the core, and within the cladding and distinct from the core, at least one visualization member facilitating visualization of one or more elements of the fiber structure.
Abstract:
Methods of tuning, switching or modulating, or, in general, changing the resonance of waveguide micro-resonators. Changes in the resonance can be brought about, permanently or temporarily, by changing the size of the micro-resonator with precision, by changing the local physical structure of the device or by changing the effective and group indices of refraction of the mode in the micro-resonator. Further changing the asymmetry of the index profile around a waveguide can alter the birefringence of the waveguide and allows one to control the polarization in the waveguide. This change in index profile may be used to change the polarization dependence or birefringence of the resonators.
Abstract:
A polarization-maintaining optical fiber and absolutely single-polarization optical fiber are provided which enable long distance transmission maintaining a polarization state of signal light. The polarization-maintaining optical fiber includes a core, photonic crystal cladding, and jacket. The photonic crystal cladding is divided into four segments by broken lines from the center to the periphery. Among a plurality of grating holes in a pair of segments opposed to each other with respect to the core, the diameter of grating holes close to the core is greater than the diameter of grating holes in another pair of segments opposed with each other, and than a grating constant.
Abstract:
A waveguide structure has a base having a base height (h) above a substrate and a rectangular waveguide having a waveguide height (H) above the substrate and a waveguide width (W) between opposing sides of the waveguide.
Abstract:
A polarized wave scrambler and an optical signal transmission apparatus in which polarization mode dispersion is suppressed, and which has first and second polarization maintaining optical fibers, wherein respective constant components of a phase difference characteristic for optical frequencies between high-speed and low-speed axes of the first and the second polarization maintaining optical fibers are equal, and respective slopes for optical frequencies of the phase difference characteristics of the first and second polarization maintaining optical fibers are different. A plane of polarization of the linearly polarized optical signal is set to an angle between the high-speed axis and the low-speed axis of the first polarization maintaining optical fiber and the linearly polarized optical signal is supplied to the first polarization maintaining optical fiber. Further, the first and the second polarization maintaining optical fibers are spliced such that the high-speed axis of the first, corresponds to the low-speed axis of the second, polarization maintaining optical fiber, and the low-speed axis of the first, corresponds to the high-speed axis of the second, polarization maintaining optical fiber.
Abstract:
The invention relates to a method of producing a preform for a holey optical fibre, and more particularly, to a method of producing polymer holey optical fibre using novel capillary and cane designs that allow a construction of complex holey structures. The capillaries may have a complex internal structure including multiple holes, holes of non-circular shape, off-centre holes, holes of different sizes, or any combination of these. The canes may have a complex external shape to define interstitial holes when the canes arc combined in a stack (see FIG. 1). The capillaries and canes may be made of different materials and combined within the same structure.
Abstract:
A method and device for measuring the current in a conductor are presented. They utilize the Faraday effect on counter-propagating circularly polarized beams of light in a fiber optic coil. The light beams are transformed to and from circular polarization by a polarization transformer comprised of a birefringent fiber with a twist through an appropriate angle at an appropriate distance from one end.