The invention concerns a method for measuring the concentration of a substance or mixture of substances and/or determining the level in a fluid with intrinsic fluorescence, preferably fuel systems. The invention also refers to the optical device suitable for implementing the method, which comprises a unit which generates light for excitation of the sample; a unit of detection of the signal emitted by the sample and a unit of signal processing. The device and method by which it is implemented also allow the determination of the spatial distribution of the substance or mixture of liquid substances and/or the fluid level in a container. One of the main applications is the measurement of the concentration of oxygen in the fuel tank of aircrafts, based on the measurement of the intrinsic fluorescence of the fuel.

A tube preparation step of preparing a resin tube that has a tube wall impregnable with a solution including a fine substance and is made of a light-transmitting resin material, a solution preparation step of preparing a solution that includes a fine fluorescent substance that emits fluorescence or a fine scattering substance that scatters light as an oscillation material and an impregnation step of causing the resin tube to be immersed in the solution and causing the tube wall of the resin tube to be impregnated with the oscillation material, are included.

For correcting aberration-induced imaging errors of an optical system which includes an objective (14) and an adaptive optic (18), light (5) and a sample (20) are selected such that the light (5), in acting upon the sample (20), reduces a measurement signal (28) from the sample (20), wherein a relative variation of the measurement signal (28) depends on the intensity of the light (5). The measurement signal (28) from a focal area of the optical system in the sample (20) is registered over a first and a later second period of time (38, 37) to determine a first measurement value and a second measurement value. Over a third period of time (39) which overlaps with the first and/or the second period of time, the light (5) is focused into the focal area by means of the optical system. A measure value for the relative variation of the measurement signal (28) is determined from the first and the second measurement values and used in controlling the adaptive optic (18) as a metric to be optimized.

A system and associated method measures anomalous diffusion of biomolecules in cell membranes of intact cells and includes a laser that illuminates a cell membrane within an intact cell to express fluorescently tagged biomolecules. The laser photobleaches a region of interest and illuminates the region of interest over time. A detector detects the fluorescence recovery over time within the region of interest to yield fluorescence recovery after photobleaching (FRAP) data. A controller computes the mean square displacement (MSD) of diffusing biomolecules and a time-dependent diffusion coefficient D(t) from a plurality of time points of the FRAP data and determines the anomalous diffusion in the cell membrane.

In a method for measuring at least two different components of a fluid, the fluid is to a first measuring cell and a second measuring cell. In the first measuring cell, a first component of the fluid is excited by a first excitation to trigger a first light emission, and in the second measuring cell, a second component of the fluid is excited by a second excitation which is different from the first excitation, thereby triggering a second light emission. The first light emission and the second light emission are captured by an optical system facility and guided by the optical system facility in a direction of a detector facility which measures the first light emission and the second light emission.

An optical apparatus having an illumination module with a carrier, which has at least one light-transmissive region, for example. The illumination module has a plurality of light sources, which are arranged on the carrier.

A method of dialysis is provided that includes sensing the concentration of potassium in a patient's blood serum, in used dialysate resulting from treating the patient, or in both. The method involves generating a sensed value of the concentration of potassium, comparing the sensed value with one or more values stored in a memory, and generating a control signal based on the comparison. Supplemental potassium solution is infused into the treatment dialysate, based on the control signal. The comparison can be made to patient-historical data, population data, or both.

A method of imaging described herein comprises (a) disposing ultrasound-switchable fluorophores within an environment; (b) exposing the environment to ultrasound to create a first activation region within the environment; (c) disposing the fluorophores within the first activation region to switch the fluorophores from an off state to an on state; (d) irradiating the environment to excite the fluorophores within the first activation region; (e) detecting photoluminescence from the excited fluorophores at a first optical spot on an exterior surface of the environment; (f) subsequently creating a second activation region within the environment; (g) switching fluorophores within the second activation region to an on state; (h) exciting the fluorophores in the on state within the second activation region; and (i) detecting photoluminescence from the excited fluorophores within the second activation region at a second optical spot on the exterior surface, wherein the first and second optical spots are optically resolvable.

A detection method based on laser-induced breakdown spectroscopy enhanced by a two-dimensional plasma grating includes: generating a femtosecond laser pulse by a femtosecond laser, and splitting the femtosecond laser pulse into three sub-pulses by a beam splitting unit; focusing the three sub-pulses separately by a focusing unit to allow focused sub-pulses to be overlapped at an intersection in space, wherein before reaching the intersection, the three sub-pulses form two planes; synchronizing the three sub-pulses in a time domain by adjusting optical paths of the three sub-pulses in such a way that they have the same optical length and the three sub-pulses arrive at the intersection in space simultaneously and form the two-dimensional plasma grating; and exciting a sample on a stage based on the two-dimensional plasma grating to generate a plasma cluster, and acquiring a spectrum of the sample.

The chemical sensing device comprises a substrate of semiconductor material, integrated circuit components and a photodetector formed in the substrate, a dielectric on the substrate, a wiring in the dielectric, and a source of electromagnetic radiation, a waveguide and a fluorescent sensor layer arranged in or above the dielectric. A portion of the waveguide is arranged to allow the electromagnetic radiation emitted by the source of electromagnetic radiation to be coupled into the waveguide. A further portion of the waveguide is arranged between the photodetector and the fluorescent sensor layer.