An optical modulator includes: a vibrator configured to perform flexural vibration along a first direction; and a diffraction grating disposed in the vibrator and having a plurality of grooves arranged in parallel along the first direction. A frequency of laser light incident on the diffraction grating is shifted. In addition, it is preferable that the vibrator includes a base portion, a first vibration arm, and a second vibration arm disposed side by side along the first direction and coupled to the base portion, the first vibration arm and the second vibration arm perform the flexural vibration along the first direction, and the diffraction grating is disposed on at least one of the first vibration arm and the second vibration arm.

A laser device includes a tunable laser having a laser cavity and a laser control module placed outside the laser cavity, the tunable laser being configured to generate laser light having a center frequency, the laser control module being configured to receive at least a portion of the laser light generated by the laser, to generate a control signal and to feed the control signal back to the laser for stabilizing the frequency, wherein the laser control module includes an interferometer having interferometer mirrors and a tunable interferometer length, and wherein the interferometer length is tunable by an actuator arranged between the interferometer mirrors and by thermal variation.

One or more devices, systems, methods and storage mediums for performing optical coherence tomography (OCT) while reducing and/or eliminating crosstalk noise are provided. Examples of such applications include imaging, evaluating and diagnosing biological objects, such as, but not limited to, for Gastro-intestinal, cardio and/or ophthalmic applications, and being obtained via one or more optical instruments, such as, but not limited to, optical probes, catheters, capsules and needles (e.g., a biopsy needle). Preferably, the OCT devices, systems methods and storage mediums include or involve a method, such as, but not limited to, a complex conjugate method or a shift method, for handling the crosstalk noise in a way to mitigate or eliminate the noise from an image field of view. For example, a reference reflection or reference arm may be positioned or re-positioned in the image field of view at different locations depending on the crosstalk noise mitigation method being employed.

Provided are improved optical detection systems and methods for using same, which systems and methods comprise single channel interferometric detection systems and methods for determining a characteristic property of samples. Such interferometric detection systems and methods employ a light beam that impinges two or more discrete zones along a channel, thereby avoiding variations that can result in increases in detection limits and/or measurement errors.

Methods, devices and systems for measuring surface roughness and surface shape of an object are described. An example interferometric system includes a collimator and a first and a second light sources with different spectral ranges and different coherence lengths. The system selectively allows light from one of the light sources to reach the collimator, and also includes a beamsplitter, and a Mirau type microscope having an objective lens, a plate with a central reflective spot and a beamsplitter plate to produce a reference beam and a test beam. An imaging lens receives the test and reference beams that form a plurality of interferograms. A neural network receives two of the interferograms for measuring the surface shape and another two interferograms for measuring the surface roughness of the object. The interferometric systems have a compact form, making them suitable for on-machine measurements and other applications.

The optical coherence tomography apparatus (100) includes a splitter/merger (104), which splits an object light beam from a wavelength sweeping laser light source (101) into a plurality of object light beams, an optical spectrum data generation unit (110), which generates information on wavelength dependence of the intensity difference among a plurality of interference light beams generated by an interference between an object light beam and a reference light beam, wherein the object light beam is generated by merging the plurality of object light beams after the plurality of object light beams are radiated to different positions on the surface of a measurement target object (200) and then scattered, and a control unit (111), which acquires structural data in the depth direction based on information on wavelength dependence and connects a plurality of sets of acquired structural data while moving the radiation position of the plurality of object light beams.

The optical coherence tomography apparatus (100) includes a splitter/merger (104), which splits an object light beam from a wavelength sweeping laser light source (101) into a plurality of object light beams, an optical spectrum data generation unit (110), which generates information on wavelength dependence of the intensity difference among a plurality of interference light beams generated by an interference between an object light beam and a reference light beam, wherein the object light beam is generated by merging the plurality of object light beams after the plurality of object light beams are radiated to different positions on the surface of a measurement target object (200) and then scattered, and a control unit (111), which acquires structural data in the depth direction based on information on wavelength dependence and connects a plurality of sets of acquired structural data while moving the radiation position of the plurality of object light beams.

Aspects of inventive concepts described herein relate to an interferometric reflectance imaging system. The system can include an imaging sensor including pixels that are preferentially sensitive to a plurality of light components; an illumination source configured to emit illumination light along an illumination path, the illumination light including the plurality of light components; and a target including a target substrate configured to support one or more nanoparticles on a surface of the target substrate. The system may be configured to, at a nominal focus position: generate an image at the imaging sensor based, at least in part, on the light reflected from the target interfering with light scattered from nanoparticles on the target substrate; and process the image to detect the nanoparticles on the target substrate.

Provided is an optical self-heterodyne detection system. The system includes a light source configured to generate light, a photodetector configured to detect the light, a programmable filter provided between the photodetector and the light source, and an electrical spectrum analyzer connected to the photodetector and configured to analyze a frequency and wavelength of the light using a detection signal of the photodetector. The light source may include a frequency comb light source.

A variable synthetic wavelength absolute distance measuring device locked to a dynamic sideband and a method thereof are disclosed. A high-frequency electro-optic phase modulator driven by an adjustable clock source to modulate a single-frequency reference laser to generate laser sidebands with equal frequency intervals. The tunable laser is locked to the fifth-order sideband through an offset frequency locking technology. After locking, the interval frequency of the sideband is determined by the adjustable clock source, namely dynamic sideband. The frequency of the adjustable clock source is dynamically adjusted, the interval frequency of the sideband and the frequency difference between the two lasers will change accordingly. Combined with the multi-wavelength interferometry, the constructed synthetic wavelength is also determined by the adjustable clock source, that is, the variable synthetic wavelength. The variable synthetic wavelength is dynamically adjusted, and the multi-level second-level synthetic wavelength is continuously constructed from large level to small level.