Abstract: A vortex optical fiber for use in an illumination subsystem of an optical imaging system (e.g., a stimulated emission depletion (STED) microscopy system) includes an elongated optically transmissive medium having a set of regions including a core region, a trench region surrounding the core region, a ring region surrounding the trench region, and a cladding region, the set of regions having a doping profile providing a ?neff for vector modes in an LP11 mode group of greater than 1×10?4 in the visible spectral range so as to simultaneously guide stable Gaussian and orbital angular momentum (OAM) carrying modes at corresponding visible wavelengths.

Abstract: A specialized, dispersion-controlled fiber is particularly configured to exhibit a relatively uniform dispersion (D) over a broad spectral range (for example, 1000 nm to 2000 nm). The specialized fiber exhibits an essentially constant attenuation (?) over this same spectral range so that the fiber is defined as having a high “figure of merit” (FoM) where FoM is defined as |D|/?. The specialized fiber is well-suited for use as a pulse stretcher, providing the ability to separate out wavelength constituents of an extremely short (fs, ps) broadband pulse into the ns range, for example.

Abstract: A specialized, dispersion-controlled fiber is particularly configured to exhibit a relatively uniform dispersion (D) over a broad spectral range (for example, 1000 nm to 2000 nm). The specialized fiber exhibits an essentially constant attenuation (?) over this same spectral range so that the fiber is defined as having a high “figure of merit” (FoM) where FoM is defined as |D|/?. The specialized fiber is well-suited for use as a pulse stretcher, providing the ability to separate out wavelength constituents of an extremely short (fs, ps) broadband pulse into the ns range, for example.

Abstract: A specialized, dispersion-controlled fiber is particularly configured to exhibit a relatively uniform dispersion (D) over a broad spectral range (for example, 1000 nm to 2000 nm). The specialized fiber exhibits an essentially constant attenuation (?) over this same spectral range so that the fiber is defined as having a high “figure of merit” (FoM) where FoM is defined as |D|/?. The specialized fiber is well-suited for use as a pulse stretcher, providing the ability to separate out wavelength constituents of an extremely short (fs, ps) broadband pulse into the ns range, for example.

Abstract: A vortex optical fiber for use in an illumination subsystem of an optical imaging system (e.g., a stimulated emission depletion (STED) microscopy system) includes an elongated optically transmissive medium having a set of regions including a core region, a trench region surrounding the core region, a ring region surrounding the trench region, and a cladding region, the set of regions having a doping profile providing a ?neff for vector modes in an LP11 mode group of greater than 1×10?4 in the visible spectral range so as to simultaneously guide stable Gaussian and orbital angular momentum (OAM) carrying modes at corresponding visible wavelengths.

Abstract: A specialized, dispersion-controlled fiber is particularly configured to exhibit a relatively uniform dispersion (D) over a broad spectral range (for example, 1000 nm to 2000 nm). The specialized fiber exhibits an essentially constant attenuation (?) over this same spectral range so that the fiber is defined as having a high “figure of merit” (FoM) where FoM is defined as |D|/?. The specialized fiber is well-suited for use as a pulse stretcher, providing the ability to separate out wavelength constituents of an extremely short (fs, ps) broadband pulse into the ns range, for example.

Abstract: A distributed Brillouin sensor system comprising a pump laser, and a combined fiber assembly including at least a first optical fiber section and a second optical fiber section is described. The pump laser is arranged so as to send a pump signal into a first end of combined fiber assembly, and the detector system is arranged to detect Brillouin backscattering from the combined fiber assembly. The combined fiber assembly is characterized by the first section having a low Brillouin gain, and the second fiber section having a high Brillouin gain.

Abstract: A distributed Brillouin sensor system comprising a pump laser, a Brillouin sensor fiber, and a detector system is described. The pump laser is arranged so as to send a pump signal into a first end of the Brillouin sensor fiber, and the detector system is arranged to detect Brillouin backscattering from the Brillouin sensor fiber. The Brillouin sensor fiber is characterized by having a negative dispersion, and further by an effective area of the sensor fiber being less than or equal to 50 ?m2.

Abstract: A distributed Brillouin sensor system comprising a pump laser, a Brillouin sensor fiber, and a detector system is described. The pump laser is arranged so as to send a pump signal into a first end of the Brillouin sensor fiber, and the detector system is arranged to detect Brillouin backscattering from the Brillouin sensor fiber. The Brillouin sensor fiber is characterized by having a negative dispersion, and further by an effective area of the sensor fiber being less than or equal to 50 ?m2.

Abstract: A few-moded fiber is doped such that spatial modes of a signal exhibit different magnetic-field-dependent effects. Based on these magnetic-field-dependent effects, one can determine the electric current that induced a magnetic field that caused these effects.

Abstract: A distributed Brillouin sensor system comprising a pump laser, and a combined fiber assembly including at least a first optical fiber section and a second optical fiber section is described. The pump laser is arranged so as to send a pump signal into a first end of combined fiber assembly, and the detector system is arranged to detect Brillouin backscattering from the combined fiber assembly. The combined fiber assembly is characterized by the first section having a low Brillouin gain, and the second fiber section having a high Brillouin gain.

Abstract: Techniques for analyzing output modal content of optical fibers that support more than one spatial mode are disclosed. These techniques are based on spatially resolving interference between co-propagating modes and constructing a spatial beat pattern between the co-propagating modes. By doing so, these techniques provide information about the modes that propagate along the optical fiber.

Abstract: An optical waveguide comprising an axial direction and a cross-section perpendicular to said axial direction is shown. The optical waveguide comprises a core region. The core region includes an integrally formed hologram, which extends along a first axial segment of the optical waveguide, the first axial segment having a first axial length. The hologram, seen in the cross-section, includes a micro-structure with written elements having a modified refractive index different from areas of the core region with an unmodified refractive index.

Abstract: A few-moded fiber is doped such that spatial modes of a signal exhibit different magnetic-field-dependent effects. Based on these magnetic-field-dependent effects, one can determine the electric current that induced a magnetic field that caused these effects.

Abstract: Systems and methods for reducing modal group delay when transmitting a plurality of optical signals over a transmission line that supports a plurality of modes are disclosed. The modes are converted at a plurality of positions along the transmission line so the signals in the end have minimal group delay. The method comprises the steps of receiving N number of optical signals into a multimode fiber having at least N modes, transmitting each of N signals into a mode of the at least N modes of the multimode fiber, and converting each of the N modes into another of the N modes at N positions along the transmission line, such that the net modal group delay generated between the N signals along the transmission line is minimized.

Abstract: Techniques for analyzing output modal content of optical fibers that support more than one spatial mode are disclosed. These techniques are based on spatially resolving interference between co-propagating modes and constructing a spatial beat pattern between the co-propagating modes. By doing so, these techniques provide information about the modes that propagate along the optical fiber.

Abstract: Described is a method of fabricating an optical fiber preform that includes a deep index trench comprising a shallower outer trench portion formed on a substrate tube and a deeper inner trench portion formed on the shallower outer trench portion. Each of the shallower outer trench and deeper inner trench portions comprises multiple silica layers. The method comprises the steps of: (1) forming each layer of the shallower outer trench portion in a single-pass deposition of a F-containing silica layer; and (2) forming each layer of the deeper inner portion in a double-pass deposition in which, in a first pass, a layer of silica soot is deposited and then, in a second pass, the soot is sintered in the presence of SiF4.

Abstract: An optical fiber that is relatively insensitive to bend loss comprises a core region and a cladding region configured to support and guide the propagation of light in a fundamental transverse mode, the cladding region including (i) an outer cladding region having a refractive index less than that of the core region, (ii) an annular cladding pedestal region having a refractive index higher than that of the outer cladding region and comparable to that of the core region, and (iii) an annular cladding inner trench region disposed between the core region and the pedestal region, the inner trench region having a refractive index less than that of the outer cladding region. In one embodiment, the fiber also includes a (iv) an annular cladding outer trench region disposed between the pedestal region and the outer cladding region, the outer trench region having a refractive index less than that of the outer cladding region.

Abstract: An optical fiber that is relatively insensitive to bend loss and alleviates the problem of catastrophic bend loss configured to support and guide the propagation of light in a fundamental transverse mode. The cladding region includes an outer cladding region, a pedestal region, an inner trench region, and an outer trench region. The pedestal region and the outer cladding region each have a refractive index relatively close to that of the outer cladding region. To suppress HOMs the pedestal region is configured to resonantly couple at least one (unwanted) transverse mode of the core region (other than the fundamental mode) to at least one transverse mode of the pedestal region. Also described are multi-tube fabrication techniques for making such fibers as well as single-pass/double-pass fabrication techniques for making the trench regions of such fibers.

Abstract: An optical fiber that is relatively insensitive to bend loss comprises a core region and a cladding region configured to support and guide the propagation of light in a fundamental transverse mode, the cladding region including (i) an outer cladding region having a refractive index less than that of the core region, (ii) an annular cladding pedestal region having a refractive index higher than that of the outer cladding region and comparable to that of the core region, and (iii) an annular cladding inner trench region disposed between the core region and the pedestal region, the inner trench region having a refractive index less than that of the outer cladding region. In one embodiment, the fiber also includes a (iv) an annular cladding outer trench region disposed between the pedestal region and the outer cladding region, the outer trench region having a refractive index less than that of the outer cladding region.