A method and system for optical vortex transmissometry. The method uses optical orbital angular momentum (OAM) and optical vortices to discriminate coherent non-scattered light from incoherent scattered light. The system includes a laser which transmits a Gaussian laser beam through a medium. An OAM generating device is placed before a photodetector receiver. Coherent, non-scattered light passing through the OAM generating device forms an optical vortex, used to discriminate against the unwanted scattered signal that does not form a vortex. Alternatively, the system includes a transmitter, which generates one or more OAM modes, which are transmitted through a turbid medium. At the receiver, an OAM detection device analyzes the OAM mode spectrum of the received light. Coherent non-scattered light retains the OAM encoded at the transmitter, while scattered light does not. The attenuation of the channel is determined by comparison of the received OAM mode spectrum relative to the transmitted OAM mode spectrum.

Methods and assemblies for aligning an optical device with a surface configured to receive a liquid coating and for measuring a parameter of a liquid coating are provided. An exemplary method for measuring a parameter of a liquid coating includes providing a mechanical carriage connected to a surface configured to receive a layer of the liquid coating. An exemplary mechanical carriage is configured to move to and from an operative configuration located at a set distance and orientation with respect to the surface. The method further includes locating an optical device in the mechanical carriage. Also, the method includes adjusting an orientation of the optical device within the mechanical carriage to an aligned orientation based on a relationship between the surface and a mechanical alignment feature on the optical device. The method further includes performing a parameter measurement operation with the optical device in the aligned orientation.

A method and system for optical vortex transmissometry. The method uses optical orbital angular momentum (OAM) and optical vortices to discriminate coherent non-scattered light from incoherent scattered light. The system includes a laser which transmits a Gaussian laser beam through a medium. An OAM generating device is placed before a photodetector receiver. Coherent, non-scattered light passing through the OAM generating device forms an optical vortex, used to discriminate against the unwanted scattered signal that does not form a vortex. Alternatively, the system includes a transmitter, which generates one or more OAM modes, which are transmitted through a turbid medium. At the receiver, an OAM detection device analyzes the OAM mode spectrum of the received light. Coherent non-scattered light retains the OAM encoded at the transmitter, while scattered light does not. The attenuation of the channel is determined by comparison of the received OAM mode spectrum relative to the transmitted OAM mode spectrum.

A method and system for optical vortex transmissometry. The method uses optical orbital angular momentum (OAM) and optical vortices to discriminate coherent non-scattered light from incoherent scattered light. The system includes a laser which transmits a Gaussian laser beam through a medium. An OAM generating device is placed before a photodetector receiver. Coherent, non-scattered light passing through the OAM generating device forms an optical vortex, used to discriminate against the unwanted scattered signal that doesn't form a vortex. Alternatively, the system includes a transmitter which generates one or more OAM modes which are transmitted through a turbid medium. At the receiver, an OAM detection device analyzes the OAM mode spectrum of the received light. Coherent non-scattered light retains the OAM encoded at the transmitter, while scattered light does not. The attenuation of the channel is determined by comparison of the received OAM mode spectrum relative to the transmitted OAM mode spectrum.

A method and system for optical vortex transmissometry. The method uses optical orbital angular momentum (OAM) and optical vortices to discriminate coherent non-scattered light from incoherent scattered light. The system includes a laser which transmits a Gaussian laser beam through a medium. An OAM generating device is placed before a photodetector receiver. Coherent, non-scattered light passing through the OAM generating device forms an optical vortex, used to discriminate against the unwanted scattered signal that doesn't form a vortex. Alternatively, the system includes a transmitter which generates one or more OAM modes which are transmitted through a turbid medium. At the receiver, an OAM detection device analyzes the OAM mode spectrum of the received light. Coherent non-scattered light retains the OAM encoded at the transmitter, while scattered light does not. The attenuation of the channel is determined by comparison of the received OAM mode spectrum relative to the transmitted OAM mode spectrum.

A method and apparatus for determining hemoglobin concentration is provided. A method aspect includes the steps of: a) depositing an unlysed, substantially undiluted blood sample into an analysis chamber adapted to quiescently hold the sample for analysis; b) imaging the sample in a region of the analysis chamber where the height of the chamber is no more than about twenty microns (20) or no less than about two microns (2), to produce image signals representative of the optical density of the imaged region; c) determining a sample representative optical density value using the image signals representative of the optical density of the imaged region; and d) determining the hemoglobin concentration of the sample using the sample representative optical density value.