Abstract: Modular systems can be used for optical analysis, including in-situ analysis, of stimulated liquids. An excitation module can include a radiation sources, e.g., a laser, LED, lamp, etc. A detection module can include one or more detectors configured to receive spectral and/or temporal information from a stimulated liquid. Such systems can be used to identify or measure optical emissions including fluorescence or scattering. The efficient excitation of liquid samples and collection of emissions from the samples provides substantial, up to four-fold increase in the emission signal over prior systems. In an example, emission measurements can be conducted in an isolated sample compartment, such as using interchangeable modules for discrete sampling, flow-through sampling, or sampling via fiber probe. The systems and methods described herein can be used to characterize natural aquatic environments, including assessments of phytoplankton pigments, biomass, structure, physiology, organic matter, and oil pollution.

Abstract: An Advanced Laser Fluorometer (ALF) can combine spectrally and temporally resolved measurements of laser-stimulated emission (LSE) for characterization of dissolved and particulate matter, including fluorescence constituents, in liquids. Spectral deconvolution (SDC) analysis of LSE spectral measurements can accurately retrieve information about individual fluorescent bands, such as can be attributed to chlorophyll-a (Chl-a), phycobiliprotein (PBP) pigments, or chromophoric dissolved organic matter (CDOM), among others. Improved physiological assessments of photosynthesizing organisms can use SDC analysis and temporal LSE measurements to assess variable fluorescence corrected for SDC-retrieved background fluorescence. Fluorescence assessments of Chl-a concentration based on LSE spectral measurements can be improved using photo-physiological information from temporal measurements.

Abstract: Modular systems can be used for optical analysis, including in-situ analysis, of stimulated liquids. An excitation module can include a radiation sources, e.g., a laser, LED, lamp, etc. A detection module can include one or more detectors configured to receive spectral and/or temporal information from a stimulated liquid. Such systems can be used to identify or measure optical emissions including fluorescence or scattering. The efficient excitation of liquid samples and collection of emissions from the samples provides substantial, up to four-fold increase in the emission signal over prior systems. In an example, emission measurements can be conducted in an isolated sample compartment, such as using interchangeable modules for discrete sampling, flow-through sampling, or sampling via fiber probe. The systems and methods described herein can be used to characterize natural aquatic environments, including assessments of phytoplankton pigments, biomass, structure, physiology, organic matter, and oil pollution.

Abstract: An Advanced Laser Fluorometer (ALF) can combine spectrally and temporally resolved measurements of laser-stimulated emission (LSE) for characterization of dissolved and particulate matter, including fluorescence constituents, in liquids. Spectral deconvolution (SDC) analysis of LSE spectral measurements can accurately retrieve information about individual fluorescent bands, such as can be attributed to chlorophyll-a (Chl-a), phycobiliprotein (PBP) pigments, or chromophoric dissolved organic matter (CDOM), among others. Improved physiological assessments of photosynthesizing organisms can use SDC analysis and temporal LSE measurements to assess variable fluorescence corrected for SDC-retrieved background fluorescence. Fluorescence assessments of Chl-a concentration based on LSE spectral measurements can be improved using photo-physiological information from temporal measurements.