Abstract: A mobility management entity (MME) information deleting method includes: receiving a message sent by a first MME; and if needed, determining whether it is necessary to delete information about the first MME according to version information about the first MME. The method further includes: receiving a message sent by a target MME, in which the message carries version information about a source MME acquired by the target MME or an indication of deleting information about the source MME added by the target MME; and deleting the information about the source MME according to the message. A network device for deleting MME information is also provided. According to the present invention, a network device, such as a home subscriber server (HSS), is capable of acquiring version information about a source MME or receiving an indication of deleting information about the source MME, so as to determine whether it is necessary to delete the information about the MME.

Abstract: A fiber-optic bundle based optical coherence tomography (OCT) probe method is demonstrated in a multimode optical fiber bundle based OCT system. The system can achieve a lateral resolution of 12 ?m and an axial resolution of 10 ?m using a super-luminescent diode source. This imaging approach eliminates any moving parts in the probe and has a primary advantage for use in extremely compact and safe OCT endoscopes to image internal organs and great potential to be combined with confocal endoscopic microscopy.

Abstract: A system for tomographic imaging includes a source of at least partially coherent radiation, a frequency-swept laser source and an interferometer. The radiation in the interferometer is phase modulated at a modulation frequency for elimination of DC and autocorrelation noises as well as the mirror image. The interference fringes of the radiation backscattered from the sample into the interferometer are detected to obtain a spectral signal. The spectral signal of the detected backscattered interference fringes is transformed to obtain a location dependent signal at each pixel location in a data window. A tomographic image of the fluid flow in the data window is generated for display and of the structure of the scanned fluid flow sample in the data window from the location dependent signal is generated.

Abstract: The invention is an apparatus and method for second harmonic optical coherence tomography of a sample comprising a laser coupled to an interferometer which has a reference arm and in a sample arm. A nonlinear crystal in the reference arm generates a second harmonic reference signal. The sample typically backscatters some second harmonic light into the sample arm. A broadband beam splitter optically coupled to the reference arm and sample arm combines the signals from the reference arm and sample arm into interference fringes and a dichroic beam splitter splits the interference fringes into a fundamental and second harmonic interference signal. A detector is optically coupled to the dichroic beam splitter detects interference fringes from which both an OCT and second harmonic OCT image can be constructed using a conventional data processor.

Abstract: A fiber-optic bundle based optical coherence tomography (OCT) probe method is demonstrated in a multimode optical fiber bundle based OCT system. The system can achieve a lateral resolution of 12 ?m and an axial resolution of 10 ?m using a super-luminescent diode source. This imaging approach eliminates any moving parts in the probe and has a primary advantage for use in extremely compact and safe OCT endoscopes to image internal organs and great potential to be combined with confocal endoscopic microscopy.

Abstract: In optical coherence tomography (OCT), Axial and lateral resolutions are determined by the source coherence length and numerical aperture of the sampling lens, respectively. While axial resolution can be improved using a broadband light source, there is a trade-off between lateral resolution and focusing depth when conventional optical elements are used. The incorporation of an axicon lens into the sample arm of the interferometer overcomes this limitation. Using an axicon lens with a top angle of 160 degrees, 10 ?m or better-lateral resolution is maintained over a focusing depth of at least 6 mm. In addition to high lateral resolution, the focusing spot intensity is approximately constant over a greater depth range.

Abstract: A phase-resolved functional optical coherence tomography system simultaneously obtains the Stokes vectors, structure, blood flow velocity, standard deviation, and birefringence images in human skin. The multifunctional images were obtained by processing the analytical interference fringe signals derived from the two perpendicular polarization detection channels. The blood flow velocity and standard deviation images were obtained by comparing the phase from the pairs of analytical signals in the neighboring A-lines in the same polarization state. The Stokes vectors were obtained by processing the analytical signals from two polarization diversity detection channels for the same reference polarization state. From the four Stokes vectors, the birefringence image, which is insensitive to the orientations of the optical axis in the sample, was obtained. Multifunctional images of a port wine stain birthmark in human skin are demonstrated.

Abstract: The Doppler bandwidth extracted from the standard deviation of the frequency shift in phase-resolved optical Doppler tomography (ODT) is used to image the velocity component transverse to the probing beam. The effective numerical aperture (NA) of the optical objective determines the slope of the dependence of the standard deviation on velocity. In the case where the angle between the probing beam and flow direction is within ±15 degrees to the perpendicular, the Doppler frequency shift is very sensitive to angle position while the Doppler bandwidth is insensitive to flow direction. Linear dependence of the flow velocity on the Doppler bandwidth allows accurate measurement of flow velocity without precise determination of flow direction. In addition, it also extends the dynamic range of the average frequency shift mapping method used in the phase-resolved ODT.

Abstract: A method for tomographic imaging comprises the steps of providing a source of at least partially coherent radiation and a frequency-swept laser source through an interferometer; phase modulating the radiation in the interferometer at a modulation frequency for elimination of DC and autocorrelation noises as well as the mirror image; detecting interference fringes of the radiation backscattered from the sample into the interferometer to obtain a spectral signal; transforming the spectral signal of the detected backscattered interference fringes to obtain a time and location dependent signal, including the Doppler shift and variance, at each pixel location in a data window; and generating a tomographic image of the fluid flow in the data window and of the structure of the scanned fluid flow sample in the data window from the time and location dependent signal. The apparatus comprises a system for tomographic imaging operating according to the above method.

Abstract: An endoscopic probe is combined with a source of radiation to measure a sample. A probe body includes a nonrotating transmission path and is communicated to the source to transmit radiation from the source from the proximal to the distal portion of the probe body. A micromotor is disposed in a distal portion of the probe body to provide a motive force. A movable scanner is coupled to the motor and is arranged and configured so that the scanner is directed toward or faces the transmission path. The scanner redirects the radiation from the source from the distal portion of the probe body into a scanned pattern onto the sample according to the motive force applied to the scanner from the motor. Back reflected radiation is received from the sample and is transmitted along the transmission path to the proximal portion of the probe body.

Abstract: The invention is an apparatus and method for second harmonic optical coherence tomography of a sample comprising a laser coupled to an interferometer which has a reference arm and in a sample arm. A nonlinear crystal in the reference arm generates a second harmonic reference signal. The sample typically backscatters some second harmonic light into the sample arm. A broadband beam splitter optically coupled to the reference arm and sample arm combines the signals from the reference arm and sample arm into interference fringes and a dichroic beam splitter splits the interference fringes into a fundamental and second harmonic interference signal. A detector is optically coupled to the dichroic beam splitter detects interference fringes from which both an OCT and second harmonic OCT image can be constructed using a conventional data processor.

Abstract: A system integration of multicomponent technologies includes an automated microfluidic probe station and the use of that station for the systematic study of nonideal, nonhomogeneous biological fluids such as blood in microfluidic chips. The probe station provides for real-time, non-invasive metrology of microfluidic chips employing optical coherence tomography and optical Doppler tomography to allow for collection of flow data at any location or depth within a microfluidics chip. Also included is a programmable fluidic loader and actuator platform as part of the probe station, and a semi-automated rapid prototyping tool used to fabricate the microfluidic chips measured on the probe station. The resulting data library produced by measurements on the probe station contains all the necessary information needed to develop mature, accurate microfluidic modeling and simulation CAD tools.

Abstract: A system integration of multicomponent technologies includes an automated microfluidic probe station and the use of that station for the systematic study of nonideal, nonhomogeneous biological fluids such as blood in microfluidic chips. The probe station provides for real-time, non-invasive metrology of microfluidic chips employing optical coherence tomography and optical Doppler tomography to allow for collection of flow data at any location or depth within a microfluidics chip. Also included is a programmable fluidic loader and actuator platform as part of the probe station, and a semi-automated rapid prototyping tool used to fabricate the microfluidic chips measured on the probe station. The resulting data library produced by measurements on the probe station contains all the necessary information needed to develop mature, accurate microfluidic modeling and simulation CAD tools.

Abstract: A phase-resolved functional optical coherence tomography system simultaneously obtains the Stokes vectors, structure, blood flow velocity, standard deviation, and birefringence images in human skin. The multifunctional images were obtained by processing the analytical interference fringe signals derived from the two perpendicular polarization detection channels. The blood flow velocity and standard deviation images were obtained by comparing the phase from the pairs of analytical signals in the neighboring A-lines in the same polarization state. The Stokes vectors were obtained by processing the analytical signals from two polarization diversity detection channels for the same reference polarization state. From the four Stokes vectors, the birefringence image, which is insensitive to the orientations of the optical axis in the sample, was obtained. Multifunctional images of a port wine stain birthmark in human skin are demonstrated.

Abstract: In optical coherence tomography (OCT), Axial and lateral resolutions are determined by the source coherence length and numerical aperture of the sampling lens, respectively. While axial resolution can be improved using a broadband light source, there is a trade-off between lateral resolution and focusing depth when conventional optical elements are used. The incorporation of an axicon lens into the sample arm of the interferometer overcomes this limitation. Using an axicon lens with a top angle of 160 degrees, 10 &mgr;m or better-lateral resolution is maintained over a focusing depth of at least 6 mm. In addition to high lateral resolution, the focusing spot intensity is approximately constant over a greater depth range.

Abstract: The Doppler bandwidth extracted from the standard deviation of the frequency shift in phase-resolved optical Doppler tomography (ODT) is used to image the velocity component transverse to the probing beam. The effective numerical aperture (NA) of the optical objective determines the slope of the dependence of the standard deviation on velocity. In the case where the angle between the probing beam and flow direction is within ±15 degrees to the perpendicular, the Doppler frequency shift is very sensitive to angle position while the Doppler bandwidth is insensitive to flow direction. Linear dependence of the flow velocity on the Doppler bandwidth allows accurate measurement of flow velocity without precise determination of flow direction. In addition, it also extends the dynamic range of the average frequency shift mapping method used in the phase-resolved ODT.

Abstract: The invention is a fast-scanning ODT system that uses phase information derived from a Hilbert transformation to increase the sensitivity of flow velocity measurements while maintaining high spatial resolution. The significant increases in scanning speed and velocity sensitivity realized by the invention make it possible to image in vivo blood flow in human skin. The method of the invention overcomes the inherent limitations of the prior art ODT by using a phase change between sequential line scans for velocity image reconstruction. The ODT signal phase or phase shifts at each pixel can be determined from the complex function, {tilde over (&Ggr;)}ODT(t), which is determined through analytic continuation of the measured interference fringes function, &Ggr;ODT(t), by use of a Hilbert transformation, by electronic phase demodulation, by optical means, or a fast Fourier transformation. The phase change in each pixel between axial-line scans is then used to calculate the Doppler frequency shift.

Abstract: Optical Doppler tomography permits imaging of fluid flow velocity in highly scattering media. The tomography system combines Doppler velocimetry with high spatial resolution of partially coherent optical interferometry to measure fluid flow velocity at discrete spatial locations. Noninvasive in vivo imaging of blood flow dynamics and tissue structures with high spatial resolutions of the order of 2 to 10 microns is achieved in biological systems. The backscattered interference signals derived from the interferometer may be analyzed either through power spectrum determination to obtain the position and velocity of each particle in the fluid flow sample at each pixel, or the interference spectral density may be analyzed at each frequency in the spectrum to obtain the positions and velocities of the particles in a cross-section to which the interference spectral density corresponds.

Abstract: All-optical devices, e.g., optical switches and modulators, and logic gates such as optical AND and OR gates, that include photochromic materials having first and second stable states, such as bacteriorhodopsin, organic fulgides, azo and fluorescent dyes, phycobiliproteins, rhodopsins, and their analogs, irradiated in a four-wave mixing geometry, are described. These devices can be used in a wide variety of systems, such as, e.g., optical signal processors and optical computers.

Abstract: A stable, image-retaining, optically switchable film produced from a purple membrane in a high-pH polyvinyl alcohol solution forms an optical memory for data storage. The film, when dry, can be exposed to light to convert BR molecules to their M state, which is stable, and which allows long-term image storage. The image can be erased by exposing the film to yellow light to thereby switch all the molecules to the M state, and then a reverse image can be obtained using blue light. By controlling the location and wavelength of the incident light, pixels can be selected and exposed for information storage.