A non-destructive method for chemical imaging with ˜1 nm to 10 μm spatial resolution (depending on the type of heat source) without sample preparation and in a non-contact manner. In one embodiment, a sample undergoes photo-thermal heating using an IR laser and the resulting increase in thermal emissions is measured with either an IR detector or a laser probe having a visible laser reflected from the sample. In another embodiment, the infrared laser is replaced with a focused electron or ion source while the thermal emission is collected in the same manner as with the infrared heating. The achievable spatial resolution of this embodiment is in the 1-50 nm range.

System for performing chemical spectroscopy on samples from the scale of nanometers to millimeters or more with a multifunctional platform combining analytical and imaging techniques including dual beam photo-thermal spectroscopy with confocal microscopy, Raman spectroscopy, fluorescence detection, various vacuum analytical techniques and/or mass spectrometry. In embodiments described herein, the light beams of a dual-beam system are used for heating and sensing.

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.

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.

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.

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.

The present disclosure is directed toward a measurement system capable of rapid spectroscopic and calorimetric analysis of the chemical makeup of a test sample. Systems in accordance with the present disclosure include a low-thermal-mass sample holder having a substrate whose surface has been engineered to create a large-area sample-collection surface. The sample holder includes an integrated temperature controller that can rapidly heat or cool the test sample. As a result, the sample holder enables differential scanning calorimetry Fourier-Transform Infrared Spectroscopy (DSC-FTIR) that can be performed in minutes rather than hours, as required in the prior art.

The present invention provides a gas measuring method based on photothermal effect in hollow-core optical fiber comprising: filling a target gas into the core of a hollow-core optical fiber; coupling a probe light and a periodically modulated pump light into the hollow-core optical fiber; absorbing the pump light by the target gas resulting in the periodic modulation of the phase of the probe light; demodulating the phase modulation information of the probe light to obtain the concentration of the target gas, wherein the pump laser is wavelength and/or amplitude modulated. In the present invention, two lasers including a pump laser and a probe laser are used for the measurement, this approach is simple and practical. Also, the use of the hollow-core optical fiber with extremely-small core area greatly increases the optical power density, thus enhances the strength of the detected photothermal signal; this method allows ppb level gas measurement with high selectivity, and is universally suitable for the detection of gases with absorption in near-infrared.

Various embodiments provide systems and methods for detecting defects in components of a fuel cell. Embodiment methods and systems for detecting a defect in an interconnect for a fuel cell system include thermally exciting the interconnect using optical radiation and/or inductive stimulation, detecting a thermal response of the interconnect, and based on the thermal response, determining the presence or absence of a defect in the interconnect, such as a lateral or through crack in the interconnect.

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.