摘要:
The present invention provides a photorefractive potassium niobate (KNbO3 ) crystal including a first impurity added substitutionally to the niobium (Nb) site and a second impurity added substitutionally to the potassium (K) site, wherein the first and second impurities are different. There is also provided a method of making the codoped potassium niobate crystal (KNbO3 ) of the present invention wherein the method includes adding at least one of the impurities to a melt composition during crystal growth, adding at least one of the impurities into an existing crystal using thermal diffusion, and/or adding at least one of impurities into an existing crystal using electrically assisted diffusion.
摘要:
Formulations for controlled, sustained release of biologically active agents for the treatment of ocular disorders have been developed. These formulations are based on solid microparticles formed of the combination of biodegradable, synthetic polymers such as poly(lactic acid) (PLA), poly(glycolic acid) (PGA), and copolymers thereof. The microparticles are characterized by low burst levels and efficient drug loading and sustained release.
摘要:
The methods disclosed herein are of use for the production of controlled release compositions. In particular, the methods provide the contacting of an organic phase containing a bioactive agent and a polymer with an aqueous phase containing an organic ion to create controlled release compositions containing bioactive agents. The present invention also includes controlled release compositions including a polymer, an organic ion and a bioactive agent. The present invention also includes methods of using such controlled release compositions. The usefulness of the present invention is that the methods result in the production of controlled release compositions containing bioactive agent capable of administration in a concentrated low-dose form, having low burst and reduced production of degraded bioactive agent.
摘要:
An optical inspection system (10) for comparing surface structures of test and reference objects comprises a laser (12), a photorefractive crystal (24) and a detector (30). A refractive index grating corresponding to a diffraction pattern of a surface structure of the reference object is present within the photorefractive crystal (24) and acts as a spatial filter for light diffracted by surface structures of the test objects. If a surface structure of a test object matches that of the reference object, little or no light reaches the detector (30). If the surface structure of a text object differs from that of the reference object, light of greater power reaches the detector (30). The system (10) provides a simple pass/fail comparison test and light incident on the detector (30) requires no interpretation or other processing. The system (10) may be adapted to allow simple imaging of an edge of an object.
摘要:
A continuous wave laser device (40) comprises a convoluted path or fiber (43) of Raman laser material that has been micromachined on to a substrate, the laser material fiber being covered by protective cladding (30). A 1 cm diameter substrate can have tens of meters of fiber fabricated on it and with a suitable choice for the laser material, e.g. Diamond, can output tens of hundreds of Watts of laser power. One possible use envisaged is as multicolor laser diodes, for example for projection television systems.
摘要:
An harmonic generator system for generating at least two output beams (6a, 6b, 6c) of higher order harmonic radiation from an input beam (1) of radiation of frequency .omega. comprises at least two non linear optical crystals (3a, 3b, 3c) arranged in series. Radiation output from each crystal stage has first and higher order harmonic components. Chromatic separators (5a, 5b, 5c) separate beams of radiation output from each crystal and selected beams are then passed through a telescope (9a, 9b) to the next crystal in the series, thereby generating further radiation beams of first and higher order harmonics. Multiple beams of second, 2.omega., third 3.omega., or fourth, 4.omega., harmonic radiation may be output from the system and may be used to pump various stages of a secondary laser system or an optical parametric oscillator. Alternatively, the output beams of higher order harmonic radiation may be coherently combined to form a single output. The system is capable of yielding considerably high conversion efficiencies, approaching 100%. The system for generating multiple beams of second harmonic radiation preferably comprises a three non linear crystals, for example potassium titanyl phosphate (KTP) or potassium dihydrogen phosphate (KDP), such that three beams of second harmonic radiation are generated. The telescope magnofications may be variable so that the relative intensity of radiation output at each crystal stage may be varied.
摘要:
The present invention provides a photorefractive hybrid cell including a window and a gain media disposed adjacent the window. The gain media includes nanoparticles therein. The window includes a material that forms a space-charge field. The gain media includes a material having refractive index properties that depend on an electric field. The nanoparticles include a coating which may include birefringent or polar molecules, other nanoparticles, organic material, or inorganic material.
摘要:
The present invention is directed to methods and apparatus for tempering the temperature of a liquid in a fluid conducting system. More particularly, some embodiments of the invention relates to tempering the temperature of water supplied to a fixture from a water heater in a fluid conducting system. The system can include a heater for heating the fluid and a diffuser for slowing the rate at which water provided to a decontamination fixture is heated.
摘要:
The present invention provides a photorefractive hybrid cell including a window and a gain media disposed adjacent the window. The gain media includes nanoparticles therein. The window includes a material that forms a space-charge field. The gain media includes a material having refractive index properties that depend on an electric field. The nanoparticles include a material which responds orientationally to the presence of an electric or magnetic field.