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.

A full-field microscopy method for detection of Brillouin-scattered light includes illuminating a two-dimensional plane in a sample with interrogating light having a first wavelength. Light emitted from the two-dimensional plane can be collected. The emitted light comprises Brillouin-scattered light resulting from interaction of the interrogating light with the sample. The Brillouin-scattered light can have a second wavelength shifted from the first wavelength. The collected light can be passed through a spectrally-selective assembly comprising a gas or vapor illuminated by pumping light. After the spectrally-selective assembly, the Brillouin-scattered light from multiple points in the two-dimensional plane in the sample can be simultaneously detected by an electro-optical sensor. In some embodiments, the spectrally-selective assembly can be altered by changing a wavelength or polarization of the pumping light to allow acquisition of a Brillouin spectrum.

Surface sensing systems and methods for imaging a scanned surface of a sample via sum-frequency vibrational spectroscopy are disclosed herein. The systems include a sample holder, a visible light source configured to direct a visible light beam incident upon a sampled location of the scanned surface and a tunable IR source configured to direct a tunable IR beam coincident with the visible light beam upon the sampled location. The systems also include a scanning structure configured to scan the visible light beam and the tunable IR beam across the scanned surface, and a light filter configured to receive an emitted beam from the scanned surface and to filter the emitted beam to generate a filtered light beam. The systems further include a light detection system configured to receive the filtered light beam, and an alignment structure. The methods include methods of operating the systems.

The present invention relates to a device (1) for characterizing an interface of a structure (6), said structure (6) comprising a solid first material and a second material, the materials being separated by said interface. The device (1) comprises: means (2) for generating a first mechanical wave; means (2) for forming Brillouin oscillations; means (10) for detecting time variation of the Brillouin oscillations; means (12) for responding to the time variation of the Brillouin oscillations to identify reflection of said first mechanical wave by said interface or transmission through said interface of a second mechanical wave interfering with the first mechanical wave; and means (13) for determining the variation in amplitude of the Brillouin oscillations before and after reflection or transmission by said interface. The invention also relates to a corresponding method of characterization.

An apparatus for super-resolution Brillouin microscopy includes a probe laser that emits a first laser beam and a first objective lens that focuses the first laser beam onto a sample. The apparatus further includes a pump laser that emits a second laser beam and a second quarter-wave plate that receives the second laser beam. The apparatus further includes a depletion laser that emits a third laser beam that passes through a phase plate to modify its wavefront phase such that the third laser beam has a donut shape, and a second objective lens that focuses the second laser beam and the third laser beam onto the sample. Characteristically, the beam spot from the depletion laser is overlaid with the Gaussian-shape beam spots of the first laser beam and the second laser beam at the same focal plane. A detector is configured to detect a stimulated Brillouin gain signal and a stimulated Brillouin loss signal.

A multimodal optical technique that can measure the mechanical, optical, and acoustical properties of the sample at microscopic resolution, which is based on the integration of a Brillouin microscope and a photoacoustic (PA) microscopy is provided. The multimodal technique not only can acquire co-registered Brillouin and PA signals of the sample but also allows us to utilize the sound speed measurements by PA to quantify the sample's refractive index, which is an essential property of the material and cannot be measured by either technique individually. We demonstrated the colocalization of Brillouin and time-resolved PA signals by measuring the interface of kerosene and 1% CuSO4 aqueous solution. In addition, we measured the refractive index of saline solutions with a precision of 0.003 and validated the result against published data. This multimodal modality could open new way for charactering biological cell and tissue in physiological and pathological conditions.

The present invention relates to a method and system for analyzing mechanical signatures of a plurality of cells for metastatic detection. Specifically, a data set characterized by at least one metric (such as Brillouin frequency shift and/or Brillouin linewidth) representing a cell mechanical signature is acquired for the plurality of cells by using a label-free Brillouin spectroscopy. A merit function is calculated based on one or more statistical characteristics of the data set, such as sensitivity and specificity. Then, the plurality of cells can be classified to detect metastatic cells based on mechanical signatures provided by the data set and an optimal metric value delivering maximum to the merit function.

A full-field microscopy method for detection of Brillouin-scattered light includes illuminating a two-dimensional plane in a sample with interrogating light having a first wavelength. Light emitted from the two-dimensional plane can be collected. The emitted light comprises Brillouin-scattered light resulting from interaction of the interrogating light with the sample. The Brillouin-scattered light can have a second wavelength shifted from the first wavelength. The collected light can be passed through a spectrally-selective assembly comprising a gas or vapor illuminated by pumping light. After the spectrally-selective assembly, the Brillouin-scattered light from multiple points in the two-dimensional plane in the sample can be simultaneously detected by an electro-optical sensor. In some embodiments, the spectrally-selective assembly can be altered by changing a wavelength or polarization of the pumping light to allow acquisition of a Brillouin spectrum.

A system and method are provided for distributed acoustic sensing in a multicore optical fiber. The system includes a transmitter for simultaneously propagating a sequence of M light pulses through the multicore optical fiber using a spatial mode selected from a set of N spatial modes provided by a spatial mode selector for the transmitter that is coupled to an input to the multicore optical fiber, with M and N being respective integers greater than one. The system further includes a receiver for receiving the sequence of M light pulses at an output of the multicore optical fiber and detecting an environmental perturbation in the multicore optical fiber based on an evaluation of a propagation of the sequence of M light pulses through the multicore optical fiber.

The present invention relates to a method and system for identifying mechanical properties of a cell nucleus through a label-free cell analysis based on Brillouin light scattering techniques. The present application additionally provides a method and system for identifying cancerous cells based on mechanical properties of the cell nucleus.