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.

Disclosed is a low-cost, portable photo thermal spectroscopy (PTS) reader for use in detecting the presence of diseases in the bodily fluid of affected patients. The PTS reader is designed to be durable, easy to use and provide readings from the Lateral Flow Assay (LFA) with rapid results. Also provided are methods of use.

Mid-infrared photothermal heterodyne imaging (MIR-PHI) techniques described herein overcome the diffraction limit of traditional MIR imaging and uses visible photodiodes as detectors. MIR-PHI experiments are shown that achieve high sensitivity, sub-diffraction limit spatial resolution, and high acquisition speed. Sensitive, affordable, and widely applicable, photothermal imaging techniques described herein can serve as a useful imaging tool for biological systems and other submicron-scale applications.

Embodiments disclosed herein are directed to photothermal spectroscopy apparatuses and systems for offset synchronous testing of flow assays. Methods of using and operating such photothermal spectroscopy systems are also disclosed.

A method and corresponding apparatus for detecting a molecule, in particular a trace gas species, in a sample using photothermal spectroscopy including the steps of providing a probe laser beam and propagating the probe laser beam to a cavity of a Fabry-Perot interferometer directing the probe laser beam through the sample in the cavity providing an excitation laser beam for heating the sample in the cavity directing the excitation laser beam through the sample in the cavity detecting the transmitted probe laser beam, which was transmitted from the cavity and detecting the reflected probe laser beam, which was reflected from the cavity.

The system includes a thermal subsystem, an optical subsystem, and a processor. The thermal subsystem comprises a first laser light source configured to emit laser light, a first focusing lens configured to direct the laser light onto a workpiece, and a thermal camera configured to capture a thermal image of the workpiece. The optical subsystem includes at least one light source configured to emit laser light with at least one illumination modality, at light focusing lens configured to direct the light onto the workpiece, and a detector configured to capture at least one image of the workpiece. The processor is configured to compare the at least one image received from the detector to at least one reference image for registration of the workpiece or to determine presence of a surface defect on the workpiece, and to determine presence of a bulk defect in the workpiece based on the thermal image.

A microscopic object detection system includes a collecting kit and a detection device. The collecting kit has a thin film for converting light into heat and is configured to be capable of holding a sample on the thin film. The detection device detects a plurality of microscopic objects in the sample by collecting the plurality of microscopic objects dispersed in the sample with the collecting kit. The detection device includes a laser module, an optical receiver, and a controller. The laser module emits a laser beam with which the collecting kit is irradiated. The optical receiver detects the laser beam from the sample held by the collecting kit and outputs a detection signal thereof. The controller calculates an amount of the plurality of microscopic objects collected in the sample based on a change of the detection signal over time.

A stimulated Raman photothermal (SRP) microscope for imaging a sample. A first optical source without an optical resonator emits a pump beam. A second optical source emits an intensity-modulated Stokes beam. The Stokes beam is combined with the pump beam to form a combined beam. The combined beam is directed to the sample to induce a thermal effect caused by the stimulated Raman process. A third optical source emits a probe beam, the probe beam is directed to the sample. An optical detector detects modulation of the probe beam after modulation by the sample to measure an SRP signal. Because noise in the pump and Stokes beam do not significantly effect the measurements from the probe beam, these beams can use a high-powered optical parametric amplifier (OPA) source for improved sensitivity and imaging speed compared to SRP microscopes using an optical parametric oscillator (OPO) source.

A stimulated Raman photothermal (SRP) microscope for imaging a sample. A first optical source without an optical resonator emits a pump beam. A second optical source emits an intensity-modulated Stokes beam. The Stokes beam is combined with the pump beam to form a combined beam. The combined beam is directed to the sample to induce a thermal effect caused by the stimulated Raman process. A third optical source emits a probe beam, the probe beam is directed to the sample. An optical detector detects modulation of the probe beam after modulation by the sample to measure an SRP signal. Because noise in the pump and Stokes beam do not significantly effect the measurements from the probe beam, these beams can use a high-powered optical parametric amplifier (OPA) source for improved sensitivity and imaging speed compared to SRP microscopes using an optical parametric oscillator (OPO) source.

Mid-infrared photothermal heterodyne imaging (MIR-PHI) techniques described herein overcome the diffraction limit of traditional MIR imaging and uses visible photodiodes as detectors. MIR-PHI experiments are shown that achieve high sensitivity, sub-diffraction limit spatial resolution, and high acquisition speed. Sensitive, affordable, and widely applicable, photothermal imaging techniques described herein can serve as a useful imaging tool for biological systems and other submicron-scale applications.