System for measuring the thickness and properties of a thin film using a spatial light modulator according to the inventive concept includes: a spatial light modulator; a first beam splitter; an objective lens; a second beam splitter; a first camera configured to acquire a surface image of the sample; an optical fiber equipped with a light receiving unit to receive reflected light passing through a certain area of a back focal plane of the objective lens; and a spectrometer configured to measure an intensity of light received from the optical fiber and output the measured intensity as an electrical signal.

Apparatus and associated methods relate to determining the wavelength of a narrow-band light beam. The narrow-band light beam is passed through an optical filter. The optical filter has complementary and monotonically-varying transmission and reflection coefficients within a predetermined band of wavelengths. The predetermined band of wavelengths includes the wavelength of the narrow-band light beam. A first photodetector detects amplitude of a first portion of the narrow-band light beam transmitted by the optical filter. A second photodetector detects amplitude of a second portion of the narrow-band light beam reflected by the optical filter. The wavelength of the narrow-band light beam is determined, based on a ratio of the determined amplitudes of the first and second portions of the narrow-band light beam transmitted and reflected, respectively.

Apparatus and associated methods relate to determining the wavelength of a narrow-band light beam. The narrow-band light beam is passed through an optical filter. The optical filter has complementary and monotonically-varying transmission and reflection coefficients within a predetermined band of wavelengths. The predetermined band of wavelengths includes the wavelength of the narrow-band light beam. A first photodetector detects amplitude of a first portion of the narrow-band light beam transmitted by the optical filter. A second photodetector detects amplitude of a second portion of the narrow-band light beam reflected by the optical filter. The wavelength of the narrow-band light beam is determined, based on a ratio of the determined amplitudes of the first and second portions of the narrow-band light beam transmitted and reflected, respectively.

An example deformable mirror includes a number of cells defining an aperture plane of the mirror. Each of the cells includes a first transparent electrode layer and a second reflective electrode layer, with a solid crystal electro-optical (EO) active layer between the electrode layers. The deformable mirror includes a reflective layer optically coupled to each of the cells on the reflective side of the cell.

An example deformable mirror includes a number of cells defining an aperture plane of the mirror. Each of the cells includes a first transparent electrode layer and a second reflective electrode layer, with a solid crystal electro-optical (EO) active layer between the electrode layers. The deformable mirror includes a reflective layer optically coupled to each of the cells on the reflective side of the cell.

The present invention relates to a microscope for quantitative measurements of the wavefront, comprising: means for the illumination of a sample (T); an objective lens (2); an ordered two-dimensional arrangement of lenses (3), with a spacing p.sub.μ greater than 500 μm and a relative aperture of less than 10; an image sensor (4) located in a capture space (Ec) to receive the light scattered by the sample (T), and to acquire spatial and angular information on the object wavefront associated therewith; and a computational entity to perform a computational reconstruction of the object wavefront from the spatial and angular information.

Other aspects of the invention relate to a method, a computer program and a product incorporating the same, adapted for the performance of the functions of the computational entity of the microscope, as well as to a module and a kit for a microscope.

The present invention relates to a microscope for quantitative measurements of the wavefront, comprising: means for the illumination of a sample (T); an objective lens (2); an ordered two-dimensional arrangement of lenses (3), with a spacing p.sub.μ greater than 500 μm and a relative aperture of less than 10; an image sensor (4) located in a capture space (Ec) to receive the light scattered by the sample (T), and to acquire spatial and angular information on the object wavefront associated therewith; and a computational entity to perform a computational reconstruction of the object wavefront from the spatial and angular information.

Other aspects of the invention relate to a method, a computer program and a product incorporating the same, adapted for the performance of the functions of the computational entity of the microscope, as well as to a module and a kit for a microscope.

A swept light source of the present invention keeps a coherence length of an output beam long over an entire sweep wavelength range. A gain of a gain medium is changed with time in response to a wavelength sweep and the coherence length is kept maximum. The gain of the gain medium is kept close to a lasing threshold and an unsaturated gain range of the gain medium is narrowed over the entire sweep wavelength range. An SOA current waveform data acquiring method of driving while keeping the coherence length long, a novel coherence length measuring method, and an optical deflector suitable for the swept light source are also disclosed.

A method for recovering missing spectral amplitude and phase information of an input real, positive valued image or signal possibly carried by incoherent or coherent waves.

Various implementations of the invention compensate for “phase wandering” in tunable laser sources. Phase wandering may negatively impact a performance of a lidar system that employ such laser sources, typically by reducing a coherence length/range of the lidar system, an effective bandwidth of the lidar system, a sensitivity of the lidar system, etc. Some implementations of the invention compensate for phase wandering near the laser source and before the output of the laser is directed toward a target. Some implementations of the invention compensate for phase wandering in the target signal (i.e., the output of the laser that is incident on and reflected back from the target). Some implementations of the invention compensate for phase wandering at the laser source and in the target signal.