Surface sensing methods for imaging a scanned surface of a sample via sum-frequency vibrational spectroscopy are disclosed herein. The methods include exposing a sampled location of the scanned surface to a visible light beam and exposing the sampled location to a tunable infrared beam such that the tunable infrared beam is at least partially coincident with the visible light beam. The methods also include varying a frequency of the tunable infrared beam an inducing optical resonance within an imaged structure that extends at least partially within the sampled location. The methods further include receiving at least a portion of an emitted light beam from the sampled location and scanning the visible light beam and the runnable infrared beam across the scanned portion of the scanned surface. The methods also include generating an image of the scanned portion of the scanned surface based upon the receiving and the scanning.

Surface sensing methods for imaging a scanned surface of a sample via sum-frequency vibrational spectroscopy are disclosed herein. The methods include exposing a sampled location of the scanned surface to a visible light beam and exposing the sampled location to a tunable infrared beam such that the tunable infrared beam is at least partially coincident with the visible light beam. The methods also include varying a frequency of the tunable infrared beam an inducing optical resonance within an imaged structure that extends at least partially within the sampled location. The methods further include receiving at least a portion of an emitted light beam from the sampled location and scanning the visible light beam and the runnable infrared beam across the scanned portion of the scanned surface. The methods also include generating an image of the scanned portion of the scanned surface based upon the receiving and the scanning.

The Raman scattering spectroscopic method according to the present invention include: preparing a chip having a channel in which a nanostructure is formed; introducing an analyte solution into a part of the channel in the chip; irradiating an interface of the analyte solution with a laser beam; and measuring Raman scattering light induced by the irradiation of the laser beam. The measurement may be performed, with a fixed laser beam irradiation position, both in a state where the interface of the analyte solution is included in the laser-beam-irradiation area and in a state where the interface of the analyte solution is not included in the laser-beam-irradiation area, or may be performed keeping the state where the interface of the analyte solution is maintained in the laser-beam-irradiation area by controlling the laser-beam-irradiation area according to the movement of the interface due to evaporation of the analyte solution.

The Raman scattering spectroscopic method according to the present invention include: preparing a chip having a channel in which a nanostructure is formed; introducing an analyte solution into a part of the channel in the chip; irradiating an interface of the analyte solution with a laser beam; and measuring Raman scattering light induced by the irradiation of the laser beam. The measurement may be performed, with a fixed laser beam irradiation position, both in a state where the interface of the analyte solution is included in the laser-beam-irradiation area and in a state where the interface of the analyte solution is not included in the laser-beam-irradiation area, or may be performed keeping the state where the interface of the analyte solution is maintained in the laser-beam-irradiation area by controlling the laser-beam-irradiation area according to the movement of the interface due to evaporation of the analyte solution.

A detection device for detecting the presence of a substance of interest in a sample is described. The device can include a data store comprising executable instructions for at least one convolutional neural network, CNN, configured to process images: and a processor coupled to the data store and configured to execute the instructions to operate the at least one CNN. The detection device can be configured to: obtain spectrometry data, operate a first one of the CNNs to process the spectrometry data to obtain a first CNN output; apply a mask to the spectrometry data to obtain masked data; operate a second one of the CNNs to process the masked data to obtain a second CNN output; and determine if the substance of interest is present in the sample based on both the first CNN output and the second CNN output.

An apparatus for carrying out polarization resolved Raman spectroscopy on a sample (11), in particular a crystalline or polycrystalline sample, the apparatus comprises: at least one light source (13, 87, 93, 95, 97), in particular at least one laser, for providing excitation radiation to a surface of the sample (11), an optical system which is configured to simultaneously collect at least one on-axis Raman beam (21, 109) and at least one off-axis Raman beam (23, 111) from Raman light scattered by the sample (11) in response to exposing the surface to the excitation radiation, the at least one on-axis Raman beam (21, 109) being scattered from the sample (11) in a direction that is aligned with an optical axis of an objective (41) of the optical system for collecting the at least one on-axis Raman beam (21, 109), the at least one off-axis Raman beam being scattered from the sample in a direction that is inclined with regard to an optical axis of an objective (41) of the optical system for collecting the at least one off-axis Raman beam (23, 111), the optical system comprises at least one polarizer device (25, 113) for generating at least one polarized on-axis Raman beam (31, 33) from the at least one on-axis Raman beam (21, 109) and at least one polarized off-axis Raman beam (35) from the at least one off-axis Raman beam (23, 111), and the optical system comprises at least one spectrometer (37, 47 81, 83, 85) for generating, in particular simultaneously, an optical spectrum from each of the at least one polarized on-axis Raman beam (31, 33) and the at least one polarized off-axis Raman beam (35).

An apparatus for carrying out polarization resolved Raman spectroscopy on a sample (11), in particular a crystalline or polycrystalline sample, the apparatus comprises: at least one light source (13, 87, 93, 95, 97), in particular at least one laser, for providing excitation radiation to a surface of the sample (11), an optical system which is configured to simultaneously collect at least one on-axis Raman beam (21, 109) and at least one off-axis Raman beam (23, 111) from Raman light scattered by the sample (11) in response to exposing the surface to the excitation radiation, the at least one on-axis Raman beam (21, 109) being scattered from the sample (11) in a direction that is aligned with an optical axis of an objective (41) of the optical system for collecting the at least one on-axis Raman beam (21, 109), the at least one off-axis Raman beam being scattered from the sample in a direction that is inclined with regard to an optical axis of an objective (41) of the optical system for collecting the at least one off-axis Raman beam (23, 111), the optical system comprises at least one polarizer device (25, 113) for generating at least one polarized on-axis Raman beam (31, 33) from the at least one on-axis Raman beam (21, 109) and at least one polarized off-axis Raman beam (35) from the at least one off-axis Raman beam (23, 111), and the optical system comprises at least one spectrometer (37, 47 81, 83, 85) for generating, in particular simultaneously, an optical spectrum from each of the at least one polarized on-axis Raman beam (31, 33) and the at least one polarized off-axis Raman beam (35).

A system for measurement is provided. The system includes a scanning interface module for placement on a skin for non-invasive scanning. The scanning interface module includes a cavity to be pressed on the skin to make a vertical portion in the cavity, and a nonlinear optical system for scanning the vertical portion via an input side and an output side of the cavity that are laterally facing each other.

A stimulated Raman scattering (SRS) spectrometer for real-time, high-resolution molecular analysis of gases is based on two hollow-core fibres illuminated by a single high-power, short-pulse laser pump. The first fibre is prefilled with high-concentration target gases. Interaction of each target gas inside the first fibre, with the laser pump, generates Raman signals corresponding to the target gases. The combined beam of the Raman signals and the pump laser beam is directed into the second fibre containing the measured target gases. Interaction of each target gas with the combined beam generates the Stimulated Raman Growth (SRG), i.e., amplification of the Raman signal, which is proportional to the corresponding target gas concentration. A receiver subsystem receives the beam from the second fibre, spectrally separates it to wavelengths corresponding to each target gas, extracts the SRG value corresponding to each target gas and calculates the concentration of each target gas.

A stimulated Raman scattering (SRS) spectrometer for real-time, high-resolution molecular analysis of gases is based on two hollow-core fibres illuminated by a single high-power, short-pulse laser pump. The first fibre is prefilled with high-concentration target gases. Interaction of each target gas inside the first fibre, with the laser pump, generates Raman signals corresponding to the target gases. The combined beam of the Raman signals and the pump laser beam is directed into the second fibre containing the measured target gases. Interaction of each target gas with the combined beam generates the Stimulated Raman Growth (SRG), i.e., amplification of the Raman signal, which is proportional to the corresponding target gas concentration. A receiver subsystem receives the beam from the second fibre, spectrally separates it to wavelengths corresponding to each target gas, extracts the SRG value corresponding to each target gas and calculates the concentration of each target gas.