An optical metrology device characterizes a test object using a phase shift interferometer with synchronous time varying optical frequency shifts. A light source generates a beam having a time varying frequency, which is divided into two collinear, orthogonally polarized beams that differ by a first frequency shift. One or more optical cavities receive the beams and produce a pair of reference beams that differ from each other in frequency by the first frequency shift and a pair of test beams with a second frequency shift induced by the one or more optical cavities. The test beams differ from each other by the first frequency shift and differ from the reference beams by the second frequency shift. The first frequency shift has a pre-defined relationship with respect to the second frequency shift to generate interference between a reference beam and test beam that have frequency shift magnitudes with the pre-defined relationship.

An optical metrology device characterizes a test object using a phase shift interferometer with synchronous time varying optical frequency shifts. A light source generates a beam having a time varying frequency, which is divided into two collinear, orthogonally polarized beams that differ by a first frequency shift. One or more optical cavities receive the beams and produce a pair of reference beams that differ from each other in frequency by the first frequency shift and a pair of test beams with a second frequency shift induced by the one or more optical cavities. The test beams differ from each other by the first frequency shift and differ from the reference beams by the second frequency shift. The first frequency shift has a pre-defined relationship with respect to the second frequency shift to generate interference between a reference beam and test beam that have frequency shift magnitudes with the pre-defined relationship.

A sensor device for use in sensing a change in a concentration of micro-organisms, comprises a waveguide interferometer having a sensing arm and a reference arm, a microfluidic channel for a fluid containing the micro-organisms, and a trapping arrangement in the microfluidic channel for physically trapping the micro-organisms when the fluid flows along the microfluidic channel so as to concentrate the micro-organisms in a sensing region of the microfluidic channel. The sensing arm is configured to guide sensing light, the reference arm is configured to guide reference light, and the waveguide interferometer is configured to interfere the sensing light with the reference light. The waveguide interferometer and the microfluidic channel are configured to allow the sensing light to interact with the fluid and the micro-organisms in the sensing region of the microfluidic channel.

A sensor device for use in sensing a change in a concentration of micro-organisms, comprises a waveguide interferometer having a sensing arm and a reference arm, a microfluidic channel for a fluid containing the micro-organisms, and a trapping arrangement in the microfluidic channel for physically trapping the micro-organisms when the fluid flows along the microfluidic channel so as to concentrate the micro-organisms in a sensing region of the microfluidic channel. The sensing arm is configured to guide sensing light, the reference arm is configured to guide reference light, and the waveguide interferometer is configured to interfere the sensing light with the reference light. The waveguide interferometer and the microfluidic channel are configured to allow the sensing light to interact with the fluid and the micro-organisms in the sensing region of the microfluidic channel.

A truncated non-linear interferometer-based sensor system includes an input that receives an optical beam and a non-linear amplifier that generates a probe beam and a conjugate beam from the optical beam. The system's local oscillators are related to the probe beam and the conjugate beam. The system includes a sensor that transduces an input with the probe beam and the conjugate beam. The transduction detects changes in the phase of each of the probe beam and the conjugate beam. The system's phase sensitive detectors detect phase modulations between the respective local oscillators, the probe beam, and the conjugate beam and outputs phase signals based on detected phase modulations. The system measures phase signals indicative of the sensor's input resulting from a sum or difference of the phase signals. The measurement exhibits a quantum noise reduction in an intensity difference, a phase sum, or an amplitude difference quadrature.

A truncated non-linear interferometer-based sensor system includes an input that receives an optical beam and a non-linear amplifier that generates a probe beam and a conjugate beam from the optical beam. The system's local oscillators are related to the probe beam and the conjugate beam. The system includes a sensor that transduces an input with the probe beam and the conjugate beam. The transduction detects changes in the phase of each of the probe beam and the conjugate beam. The system's phase sensitive detectors detect phase modulations between the respective local oscillators, the probe beam, and the conjugate beam and outputs phase signals based on detected phase modulations. The system measures phase signals indicative of the sensor's input resulting from a sum or difference of the phase signals. The measurement exhibits a quantum noise reduction in an intensity difference, a phase sum, or an amplitude difference quadrature.

A high spatial and temporal resolution synthetic aperture phase microscopy (HISTR-SAPM) system and methods are provided for sample imaging and metrology. The HISTR-SAPM system includes a sample-illumination path along which a first illumination beam propagates and a reference-beam path along which a second illumination beam propagates. A first digital micromirror device (DMD), a second DMD, and a first scanning objective lens are disposed in the sample-illumination path and at a first side adjacent to the sample. A second scanning objective lens passes the sample information to a beam splitter (BS), where the sample illumination beam and the reference-beam are combined to form an interferogram at a final image plane for imaging the sample. A Fourier spatial spectrum analysis and a synthetic aperture are then used to reconstruct a quantitative phase map of the sample with a high resolution and at a high-speed.

A high spatial and temporal resolution synthetic aperture phase microscopy (HISTR-SAPM) system and methods are provided for sample imaging and metrology. The HISTR-SAPM system includes a sample-illumination path along which a first illumination beam propagates and a reference-beam path along which a second illumination beam propagates. A first digital micromirror device (DMD), a second DMD, and a first scanning objective lens are disposed in the sample-illumination path and at a first side adjacent to the sample. A second scanning objective lens passes the sample information to a beam splitter (BS), where the sample illumination beam and the reference-beam are combined to form an interferogram at a final image plane for imaging the sample. A Fourier spatial spectrum analysis and a synthetic aperture are then used to reconstruct a quantitative phase map of the sample with a high resolution and at a high-speed.

Laser light is emitted from a laser into a scattering layer. An ultrasound signal is emitted into a sample. A signal is generated with a light detector in response to a measurement beam of laser light exiting the light scattering layer into the light detector. At least a portion of the measurement beam formed between the laser and the light detector is wavelength-shifted by the ultrasound signal subsequent to the ultrasound signal propagating through the sample.

Methods and systems for detecting and classifying defects based on the phase of dark field scattering from a sample are described herein. In some embodiments, throughput is increased by detecting and classifying defects with the same optical system. In one aspect, a defect is classified based on the measured relative phase of scattered light collected from at least two spatially distinct locations in the collection pupil. The phase difference, if any, between the light transmitted through any two spatially distinct locations at the pupil plane is determined from the positions of the interference fringes in the imaging plane. The measured phase difference is indicative of the material composition of the measured sample. In another aspect, an inspection system includes a programmable pupil aperture device configured to sample the pupil at different, programmable locations in the collection pupil.