Systems and methods according to exemplary embodiments of the present disclosure can be provided that can efficiently detect the amplitude and phase of a spectral modulation. Such exemplary scheme can be combined with self-interference fluorescence to facilitate a highly sensitive depth localization of self-interfering radiation generated within a sample. The exemplary system and method can facilitate a scan-free depth sensitivity within the focal depth range for microscopy, endoscopy and nanoscopy.

A pressure cell includes a metal pressure chamber, a heating stage, disposed in the interior of the metal pressure chamber, that heats the liquid sample, a chamber pump, connected to the interior of the metal pressure chamber, that pressurizes the interior of the metal pressure chamber, a salinity control system including a membrane coupled to the sample inlet, where the membrane is configured to reduce a salinity level of the liquid sample, and a controller that controls the chamber pump, the salinity control system, and the heating stage to control a pressure of the interior of the metal pressure chamber, a salinity level of the liquid sample, and a temperature of the liquid sample, respectively. The metal pressure chamber includes a liquid sample holder, a removable lid, a window in the removable lid, a sample inlet, and a sample outlet.

Apparatus for hyperspectral imaging, the apparatus including input optics that receive radiation reflected or radiated from a scene, a spatial modulator that spatially samples radiation received from the input optics to generate spatially sampled radiation, a spectral modulator that spectrally samples the spatially sampled radiation received from the spatial modulator to generate spectrally sampled radiation, a sensor that senses spectrally sampled radiation received from the spectral modulator and generates a corresponding output signal and at least one electronic processing device that controls the spatial and spectral modulators to cause spatial and spectral sampling to be performed, receives output signals and processes the output signals in accordance with performed spatial and spectral sampling to generate a hyperspectral image.

Pressure variations within a solid propellant rocket motor produce like variations in the optical radiance of the motor exhaust plume. The periodicity of the variation is related to the length L of the rocket motor or speed of sound in the rocket motor combustion chamber to length ratio a/L. The optical radiance is collected and converted to electrical signals that are sampled at or above the Nyquist rate. An array of single-pixel photo detectors is well suited to provide amplitude data at high sample rates. The sampled data from the one or more detectors is assembled to form a high fidelity time sequence. A window of sampled data is processed to form a signal frequency spectrum. The mode structure in the frequency spectrum is related to the rocket motor length or speed of sound in the rocket motor chamber to length ratio. The rocket motor length or speed of sound to length ratio is used alone or in combination with other information to either classify or identify the rocket motor.

Pressure variations within a solid propellant rocket motor produce like variations in the optical radiance of the motor exhaust plume. The periodicity of the variation is related to the length L of the rocket motor or speed of sound in the rocket motor combustion chamber to length ratio a/L. The optical radiance is collected and converted to electrical signals that are sampled at or above the Nyquist rate. An array of single-pixel photo detectors is well suited to provide amplitude data at high sample rates. The sampled data from the one or more detectors is assembled to form a high fidelity time sequence. A window of sampled data is processed to form a signal frequency spectrum. The mode structure in the frequency spectrum is related to the rocket motor length or speed of sound in the rocket motor chamber to length ratio. The rocket motor length or speed of sound to length ratio is used alone or in combination with other information to either classify or identify the rocket motor.

A system and method of non-contact measurement of the dopant content of semiconductor material by reflecting infrared (IR) radiation off of the material into an integrating sphere to scatter the received radiation and passing portions of the radiation through band pass filters of differing wavelength ranges, comparing the level of energy passed through each filter and calculating the dopant content by referencing a correlation curve made up of known wafer dopant content for that system.

A system and method of non-contact measurement of the dopant content of semiconductor material by reflecting infrared (IR) radiation off of the material into an integrating sphere to scatter the received radiation and passing portions of the radiation through band pass filters of differing wavelength ranges, comparing the level of energy passed through each filter and calculating the dopant content by referencing a correlation curve made up of known wafer dopant content for that system.

Aspects of the disclosure include suppression of optical interference fringes in optical spectra via a modification to the refractive index of media that forms or is contained in one or more components of equipment utilized for optical spectroscopy. Such a modification can yield changes in the optical path of light propagating through at least one of the media, with the ensuing changes in the spectral structure of interference between light propagating through different optical paths. In certain embodiments, the refractive index of the media that forms or is contained in one or more components can be modified via application of a time-dependent stimulus to at least one of the one or more components. The applied stimulus can include pressure, mechanical strain or stress, temperature, a combination thereof, or the like.

Aspects of the disclosure include suppression of optical interference fringes in optical spectra via a modification to the refractive index of media that forms or is contained in one or more components of equipment utilized for optical spectroscopy. Such a modification can yield changes in the optical path of light propagating through at least one of the media, with the ensuing changes in the spectral structure of interference between light propagating through different optical paths. In certain embodiments, the refractive index of the media that forms or is contained in one or more components can be modified via application of a time-dependent stimulus to at least one of the one or more components. The applied stimulus can include pressure, mechanical strain or stress, temperature, a combination thereof, or the like.

The present invention concerns a method for determining at least one absorption band in a spectrum, the method at least comprising the steps of:—providing a measured absorption spectrum from the sample,—providing a calculation spectrum,—from the calculation spectrum, extracting at least one absorption band,—calculating a residual spectrum by removing each extracted absorption band from the calculation spectrum, testing whether a predefined stop criterion is fulfilled by the residual spectrum,—if the stop criterion is not fulfilled, using the residual spectrum as the calculation spectrum and iterating the extracting step, the forming step, the calculating step and the testing step, and—if the stop criterion is fulfilled, outputting each extracted absorption band.