Systems and methods are provided for performing photothermal dynamic imaging. An exemplary method includes: scanning a sample to produce a plurality of raw photothermal dynamic signals; receiving the raw photothermal dynamic signals of the sample; generating a plurality of second signals by matched filtering the raw photothermal dynamic signals to reject non-modulated noise; and performing an inverse operation on the second signals to retrieve at least one thermodynamic signal in a temporal domain.

Systems and methods are provided for performing photothermal dynamic imaging. An exemplary method includes: scanning a sample to produce a plurality of raw photothermal dynamic signals; receiving the raw photothermal dynamic signals of the sample; generating a plurality of second signals by matched filtering the raw photothermal dynamic signals to reject non-modulated noise; and performing an inverse operation on the second signals to retrieve at least one thermodynamic signal in a temporal domain.

Systems and methods are provided for performing thermophotonic imaging using cross-correlation and subsequent time-gated truncation. Photothermal radiation is detected with an infrared camera while exciting a sample with a chirped set of incident optical pulses and time-dependent photothermal signal data is processed using a method that involves performing cross-correlation and subsequent time-gated truncation. The post-cross-correlation truncation method results in depth-resolved images with axial and lateral resolution beyond the well-known thermal-diffusion-length-limited, depth-integrated nature of conventional imaging modalities. An axially resolved photothermal image sequence can be obtained, capable of reconstructing three-dimensional visualizations of photothermal features in wide classes of materials.

Embodiments disclosed include methods and apparatus for Fluorescent Enhanced Photothermal Infrared (FE-PTIR) spectroscopy and chemical imaging, which enables high sensitivity and high spatial resolution measurements of IR absorption with simultaneous confocal fluorescence imaging. In various embodiments, the FE-PTIR technique utilizes combined/simultaneous OPTIR and fluorescence imaging that provides significant improvements and benefits compared to previous work by simultaneous detection of both IR absorption and confocal fluorescence using the same optical detector at the same time.

A method and apparatus for detecting a photoacoustic light signal to prevent unauthorized voice commands for a microphone-controllable device are provided. The method includes receiving, by a processor, a signal, detecting, by the processor, that the signal is a photoacoustic signal generated by a thermal expansion and contraction of an object caused by at least one lightwave applied to the object, and activating, by the processor, a counter-measure to prevent the photoacoustic signal from reaching a microphone of a microphone-controllable device in response to detecting the photoacoustic signal.

Asymmetric interferometry is used with various embodiments of Optical Photothermal Infrared (OPTIR) systems to enhance the signal strength indicating the photothermal effect on a sample.

A method and apparatus for analyzing a substance is disclosed. An optical medium is arranged on a substance surface with at least one region of the optical medium surface in contact with the substance surface. An excitation light beam is emitted through the contacting region of the medium surface (to the substance surface. A measurement light beam is emitted through the optical medium to the contacting region of the medium surface such that the measurement light beam and the excitation light beam overlap on the interface of the optical medium and of the substance surface, on which the measurement light beam is reflected. A deflection of the reflected measurement light beam is detected in dependence on the wavelength of the excitation light beam. The substance is then analyzed based on the detected deflection of the measurement light beam in dependence on the wavelength of the excitation light beam.

Systems and methods for sensing vibrational absorption induced photothermal effect via a visible light source. A Mid-infrared photothermal probe (MI-PTP, or MIP) approach achieves 10 mM detection sensitivity and sub-micron lateral spatial resolution. Such performance exceeds the diffraction limit of infrared microscopy and allows label-free three-dimensional chemical imaging of live cells and organisms. Distributions of endogenous lipid and exogenous drug inside single cells can be visualized. MIP imaging technology may enable applications from monitoring metabolic activities to high-resolution mapping of drug molecules in living systems, which are beyond the reach of current infrared microscopy.

A method and apparatus for detecting a photoacoustic light signal to prevent unauthorized voice commands for a microphone-controllable device are provided. The method includes receiving, by a processor, a signal, detecting, by the processor, that the signal is a photoacoustic signal generated by a thermal expansion and contraction of an object caused by at least one lightwave applied to the object, and activating, by the processor, a counter-measure to prevent the photoacoustic signal from reaching a microphone of a microphone-controllable device in response to detecting the photoacoustic signal.

Microscopic analysis of a sample includes a fluorescent dye disposed within the sample. A mid-IR optical source generates a mid-infrared beam, which is directed onto the sample to induce a temperature change by absorption of the mid-infrared beam. An optical source generates a probe beam directed to impinge on the sample. A detector detects fluorescent emissions from the sample when the probe beam impinges on the sample. A data acquisition and processing system acquires and processes the detected fluorescent emissions from the sample to: (i) generate a signal indicative of infrared absorption by the sample, (ii) generate a signal indicative of temperature in the sample based on the signal indicative of infrared absorption by the sample, (iii) generate an image of the sample using the signal indicative of temperature in the sample.