Abstract: Preferred embodiments of the present invention are directed to systems for phase measurement which address the problem of phase noise using combinations of a number of strategies including, but not limited to, common-path interferometry, phase referencing, active stabilization and differential measurement. Embodiment are directed to optical devices for imaging small biological objects with light. These embodiments can be applied to the fields of, for example, cellular physiology and neuroscience. These preferred embodiments are based on principles of phase measurements and imaging technologies. The scientific motivation for using phase measurements and imaging technologies is derived from, for example, cellular biology at the sub-micron level which can include, without limitation, imaging origins of dysplasia, cellular communication, neuronal transmission and implementation of the genetic code.

Abstract: Preferred embodiments of the present invention are directed to systems for phase measurement which address the problem of phase noise using combinations of a number of strategies including, but not limited to, common-path interferometry, phase referencing, active stabilization and differential measurement. Embodiment are directed to optical devices for imaging small biological objects with light. These embodiments can be applied to the fields of, for example, cellular physiology and neuroscience. These preferred embodiments are based on principles of phase measurements and imaging technologies. The scientific motivation for using phase measurements and imaging technologies is derived from, for example, cellular biology at the sub-micron level which can include, without limitation, imaging origins of dysplasia, cellular communication, neuronal transmission and implementation of the genetic code.

Abstract: Preferred embodiments of the present invention are directed to systems for phase measurement which address the problem of phase noise using combinations of a number of strategies including, but not limited to, common-path interferometry, phase referencing, active stabilization and differential measurement. Embodiment are directed to optical devices for imaging small biological objects with light. These embodiments can be applied to the fields of, for example, cellular physiology and neuroscience. These preferred embodiments are based on principles of phase measurements and imaging technologies. The scientific motivation for using phase measurements and imaging technologies is derived from, for example, cellular biology at the sub-micron level which can include, without limitation, imaging origins of dysplasia, cellular communication, neuronal transmission and implementation of the genetic code.

Abstract: The methods of the present invention are directed at an accurate phase-based technique for measuring arbitrarily long optical distances with sub-nanometer precision. A preferred embodiment of the present invention method employs a interferometer, for example, a Michelson interferometer, with a pair of harmonically related light sources, one continuous wave (CW) and a second source having low coherence. By slightly adjusting the center wavelength of the low coherence source between scans of the target sample, the phase relationship between the heterodyne signals of the CW and low coherence light is used to measure the separation between reflecting interfaces with sub-nanometer precision. As the preferred embodiment of this method is completely free of 2? ambiguity, an issue that plagues most phase-based techniques, it can be used to measure arbitrarily long optical distances without loss of precision.

Abstract: The present invention relates to systems and methods of field-based light scattering spectroscopy. These systems and methods provide for the diagnosis of tissue by measuring the size and distribution of cellular characteristics. Field based measurements provide phase information resulting from the interaction of scatterers within the material and the incident wavefront. These measurements can be used to provide three dimensional images of tissue.

Abstract: The present invention relates to the use of polarized light to measure properties of tissue. More particularly, polarized light can be used to detect dysplasia in tissue as the polarization of back-scattered light from such tissues is preserved while the contribution of diffusely scattered light from underlying tissues can be removed. A fiber optic system for delivery and collection of light can be used to measure tissues within the human body.

Abstract: The methods of the present invention are directed at an accurate phase-based technique for measuring arbitrarily long optical distances with sub-nanometer precision. A preferred embodiment of the present invention method employs a interferometer, for example, a Michelson interferometer, with a pair of harmonically related light sources, one continuous wave (CW) and a second source having low coherence. By slightly adjusting the center wavelength of the low coherence source between scans of the target sample, the phase relationship between the heterodyne signals of the CW and low coherence light is used to measure the separation between reflecting interfaces with sub-nanometer precision. As the preferred embodiment of this method is completely free of 2&pgr; ambiguity, an issue that plagues most phase-based techniques, it can be used to measure arbitrarily long optical distances without loss of precision.

Abstract: Photon migration methods are employed to image absorbing objects embedded in a turbid medium such as tissue. For improved resolution, early arriving photons are detected to provide data with image reconstruction based on optical computed tomography (CT). The CT method is generalized to take into account the distributions of photon paths. A point spread function (PSF) is expressed in terms of the Green's function for the transport equation. This PSF provides weighting functions for use in a generalized series expansion method. Measurements of turbid medium with scattering and absorption properties included coaxial transmission scans collected in two projections. Blurring associated with multiple scattering was removed and high-resolution images can be obtained.

Abstract: Surface-enhanced spectroscopy, such as surface-enhanced Raman spectroscopy employs aggregates that are of a size that allows easy handling. The aggregates are generally at least about 500 nm in dimension. The aggregates can be made of metal particles of size less than 100 nm, allowing enhanced spectroscopic techniques that operate at high sensitivity. This allows the use of larger, easily-handleable aggregates. Signals are determined that are caused by single analytes adsorbed to single aggregates, or single analytes adsorbed on a surface. The single analytes can be DNA or RNA fragments comprising at least one base.

Abstract: The present invention relates to systems and methods of field-based light scattering spectroscopy. These systems and methods provide for the diagnosis of tissue by measuring the size and distribution of cellular characteristics. Field based measurements provide phase information resulting from the interaction of scatterers within the material and the incident wavefront. These measurements can be used to provide three dimensional images of tissue.

Abstract: A method for laser induced fluorescence of tissue in which laser radiation is used to illuminate and induce fluorescence in the tissue under study to determine the chemical composition or pathologic condition of tissue. The laser radiation and the retrieved fluorescing radiation can be conveyed through a catheter using an array of optical fiber. The fluorescence spectrum of the tissue can be displayed and analyzed to obtain information regarding the chemical composition and medical condition of the tissue inside the human body.

Abstract: A method for laser induced fluorescence of tissue in which laser radiation is used to illuminate and induce fluorescence in the tissue under study to determine the chemical composition or pathologic condition of tissue. The laser radiation and the retrieved fluorescing radiation can be conveyed through a catheter using an array of optical fiber. The fluorescence spectrum of the tissue can be displayed and analyzed to obtain information regarding the chemical composition and medical condition of the tissue inside the human body.