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 totagram is produced by an iterative spectral phase recovery process resulting in complete information recovery using special masks, without a reference beam. Using these special masking systems reduce computation time, number of masks, and number of iterations. The special masking system is (1) a unity mask together with one or more bipolar binary masks with elements equal to 1 and −1, or (2) a unity mask together with one or more phase masks, or (3) a unity mask together with one pair of masks or more than one pair of masks having binary amplitudes of 0's and 1's, in which the masks in the pair are complementary to each other with respect to amplitude, or (4) one or more pairs of complementary masks with binary amplitudes of 0's and 1's without a unity mask.

A method for determining wavefront shapes of a multi-spectral signal light beam from a single signal image acquisition of said multi-spectral signal beam, with a device including an optical assembly made at least of an optical mask and an imaging sensor, notably a matrix imaging sensor, for generating and recording intensity patterns of incident beams, by having these beams reflect on, or propagate through, the optical mask. The optical mask having the optical properties: i) to cause the intensity pattern to depend on the wavefront shape, so that a tilt applied to the wavefront shape results in a displacement amount of the intensity pattern, and ii) to produce uncorrelated intensity patterns over at least one surface area A of the imaging sensor, for a plurality of respective incident monochrome beams of different wavelengths having a same wavefront shape.

A method for determining wavefront shapes of a multi-spectral signal light beam from a single signal image acquisition of said multi-spectral signal beam, with a device including an optical assembly made at least of an optical mask and an imaging sensor, notably a matrix imaging sensor, for generating and recording intensity patterns of incident beams, by having these beams reflect on, or propagate through, the optical mask. The optical mask having the optical properties: i) to cause the intensity pattern to depend on the wavefront shape, so that a tilt applied to the wavefront shape results in a displacement amount of the intensity pattern, and ii) to produce uncorrelated intensity patterns over at least one surface area A of the imaging sensor, for a plurality of respective incident monochrome beams of different wavelengths having a same wavefront shape.

An apparatus for characterization of one or more light sources, has an image sensor array that defines an image plane having an imaging area. An aperture spaced apart from the image plane defines the field of view that includes, for each of the one or more light sources, a corresponding incident light path that lies along a central ray beginning at the corresponding light source, extending through a center of the aperture, and terminating at the image plane. A diffraction grating forms, on the image sensor array, for each corresponding light source, a light pattern having at least a zeroth diffraction order and a first diffraction order, wherein the zeroth diffraction order is a geometrical projection of the aperture along the central ray. A control logic processor identifies a wavelength range and angular direction within the field of view for at least one of the light sources.

A measurement apparatus including an illumination system configured to illuminate a target with light including light of a first wavelength and light of a second wavelength, a wavefront changing unit configured to change a wavefront aberration in light from the target, and a control unit configured to control the wavefront changing unit, wherein the wavefront changing unit includes a first region where the light of the first wavelength enters, and a second region where the light of the second wavelength enters, and the control unit controls the wavefront changing unit such that a first correction wavefront for correcting a first wavefront aberration in the light of the first wavelength is generated in the first region, and a second correction wavefront for correcting a second wavefront aberration in the light of the second wavelength is generated in the second region.

A measurement apparatus including an illumination system configured to illuminate a target with light including light of a first wavelength and light of a second wavelength, a wavefront changing unit configured to change a wavefront aberration in light from the target, and a control unit configured to control the wavefront changing unit, wherein the wavefront changing unit includes a first region where the light of the first wavelength enters, and a second region where the light of the second wavelength enters, and the control unit controls the wavefront changing unit such that a first correction wavefront for correcting a first wavefront aberration in the light of the first wavelength is generated in the first region, and a second correction wavefront for correcting a second wavefront aberration in the light of the second wavelength is generated in the second region.

A beam director system for a high-energy laser (HEL) weapon includes correction sensors that are able detect misalignments in optical elements throughout the entire optical path traversed by the high-energy laser. The system includes beam correction sensors that sense misalignments in a first part of the optical path, and high-speed track sensors that sense misalignments in a second part of the optical path, with the first part and the second part overlapping. This allows all optics to be sensed by the beam correction sensors and/or the high-speed track sensors. The system can accommodate a wide variety of lasers for the HEL, preferably including a co-boresighted and aligned alignment laser. By having the track sensors further downstream on the optical path than in prior devices, the acquisition and track sensor fields of view of the system may be improved.

A beam director system for a high-energy laser (HEL) weapon includes correction sensors that are able detect misalignments in optical elements throughout the entire optical path traversed by the high-energy laser. The system includes beam correction sensors that sense misalignments in a first part of the optical path, and high-speed track sensors that sense misalignments in a second part of the optical path, with the first part and the second part overlapping. This allows all optics to be sensed by the beam correction sensors and/or the high-speed track sensors. The system can accommodate a wide variety of lasers for the HEL, preferably including a co-boresighted and aligned alignment laser. By having the track sensors further downstream on the optical path than in prior devices, the acquisition and track sensor fields of view of the system may be improved.

A method for high-accuracy wavefront measurement based on grating shearing interferometry, which adopts a grating shearing interferometer system comprising an illuminating system, an optical imaging system under test, an object plane diffraction grating plate, an image plane diffraction grating plate, a two-dimensional photoelectric sensor, and a calculation processing unit. The object plane diffraction grating plate and the image plane diffraction grating plate are respectively arranged on the object plane and the image plane of the optical imaging system under test. The shearing phase of 1.sup.st-order diffracted beam and −1.sup.st-order diffracted beam is exactly extracted through phase shifting method, and the original wavefront is obtained by carrying out reconstruction algorithm according to a shear ratio of 2s, such that the accuracy of wavefront measurement of the optical imaging system under test is improved, wherein s is the shear ratio of the grating shearing interferometer.