Abstract: Refractive index writing system and methods employing a pulsed laser source for providing a pulsed laser output at a first wavelength; an objective lens for focusing the pulsed laser output to a focal spot in an optical material; a scanner for relatively moving the focal spot with respect to the optical material at a relative speed and direction along a scan region for writing one or more traces in the optical material defined by a change in refractive index; and a controller for controlling laser exposures along the one or more traces in accordance with a calibration function for the optical material to achieve a desired refractive index profile in the optical material. The refractive index writing system may be for writing traces in in vivo optical tissue, and the controller may be configured with a calibration function obtained by calibrating refractive index change induced in enucleated ocular globes.

Abstract: Refractive index writing system and methods employing a pulsed laser source for providing a pulsed laser output at a first wavelength; an objective lens for focusing the pulsed laser output to a focal spot in an optical material; a scanner for relatively moving the focal spot with respect to the optical material at a relative speed and direction along a scan region for writing one or more traces in the optical material defined by a change in refractive index; and a controller for controlling laser exposures along the one or more traces in accordance with a calibration function for the optical material to achieve a desired refractive index profile in the optical material. The refractive index writing system may be for writing traces in in vivo optical tissue, and the controller may be configured with a calibration function obtained by calibrating refractive index change induced in enucleated ocular globes.

Abstract: Refractive index writing system and methods employing a pulsed laser source for providing a pulsed laser output at a first wavelength; an objective lens for focusing the pulsed laser output to a focal spot in an optical material; a scanner for relatively moving the focal spot with respect to the optical material at a relative speed and direction along a scan region for writing one or more traces in the optical material defined by a change in refractive index; and a controller for controlling laser exposures along the one or more traces in accordance with a calibration function for the optical material to achieve a desired refractive index profile in the optical material. The refractive index writing system may be for writing traces in in vivo optical tissue, and the controller may be configured with a calibration function obtained by calibrating refractive index change induced in enucleated ocular globes.

Abstract: A viscoelastic composition containing an effective amount of at least one cationic carbohydrate ether having one or more cationic fragments and one or more carbohydrate fragments connected through one or more linker fragments for controlling the viscoelasticity of the composition, wherein at least some carbohydrate fragments are connected to the linker fragments through ether bonds. The viscoelastic composition of the present technology may be used to alter fluid rheology and impart both viscous and elastic properties to the treated fluids. Applications of the viscoelastic composition of the present technology include, but are not limited to, oil field fluids such as, for example, well bore treatment fluids.

Abstract: A waveguide, such as a holey fiber or other optical fiber, is tapered to control the dispersion in a manner which varies along the length of the tapered portion of the fiber, thus providing the desired characteristics of the fiber. The longitudinal variation of the phase-matching conditions for Cherenkov radiation (CR) and four-wave mixing (FWM) introduced by DMM allow the generation of low-noise supercontinuum. The flexibility of the design permits the designer to control the tapering to select the bandwidth, the center frequency, or both. The holey fiber can be a polarization-maintaining fiber.

Abstract: An optical fiber is tapered, for example, by heating it with a CO2 laser. The tapering process is controlled such that the taper transition regions have taper angles selected to minimize loss. The taper waist has a diameter selected to introduce desired dispersion properties and desired nonlinearity. The optical fiber can be used as a dispersion compensator in a fiber laser or other fiber optic system. The nonlinearity in the tapered optical fiber allows the generation of ultrashort light pulses.