34results about How to "Reduce spatial coherence" patented technology

The present invention is related to a compact microscope able to work in digital holography for obtaining high quality 3D images of samples, including fluorescent samples and relatively thick samples such as biological samples, said microscope comprising illumination means (1,41) at least partially spatially coherent for illuminating a sample (2) to be studied and a differential interferometer (5) for generating interfering beams from said sample (2) on the sensor (33) of an electronic imaging device (7), said interferometer (5) comprising namely tilting means (17) for tilting by a defined angle one the interfering beams (28 or 29) relatively to the other, said tilting resulting into a defined shift (27) of said interfering beam on the sensor of the electronic imaging device (7), said shift (27) being smaller than spatial coherence width of each beam, said microscope being able to be quasi totally preadjusted independently from the samples so that minimum additional adjustments are required for obtaining reliable 3D images of samples.

A measuring device for interferometric measurement of an optical imaging system that is provided for projecting a useful pattern, provided on a mask, into the image plane of the imaging system, includes a wavefront source for generating at least one wavefront traversing the imaging system; a diffraction grating, arrangeable downstream of the imaging system, for interacting with the wavefront reshaped by the imaging system; and a spatially resolving detector, assigned to the diffraction grating, for acquiring interferometric information. The wavefront source has at least one measuring pattern that is formed on the mask in addition to the useful pattern. The useful pattern may represent the structure of a layer of a semiconductor component in a specific fabrication step. The measuring pattern may be formed as a coherence-forming structure periodic in one or two dimensions.

The invention provides a deep-ultraviolet lithography illumination system which comprises a deep-ultraviolet laser source, a cylindrical beam expander sub-system, a spherical beam expander sub-system, a compound eye light evening sub-system, a condenser sub-system, a round diaphragm and an aperture diaphragm, wherein the order of the components along the advancing direction of the laser path is as follows: the deep-ultraviolet laser source, the cylindrical beam expander sub-system, the round diaphragm, the spherical beam expander sub-system, the compound eye light evening sub-system, the aperture diaphragm and the condenser sub-system; the aperture diaphragm is located on the front focal surface of the condenser sub-system; and the centers of the components are superposed with the center of a laser beam. The deep-ultraviolet lithography illumination system provided by the invention adopts a simple spherical and cylindrical structure, and can meet the requirements of a lithography illumination system.

A speckle-free imaging light source based on a random fiber laser (RFL) using a strong-coupling multi-core optical fiber, relating to a field of optical fiber laser illumination light source, is provided, mainly including a pumping source and an optical fiber loop mirror, and further including the strong-coupling multi-core optical fiber with/without a single-mode optical fiber. Through directly adopting the strong-coupling multi-core optical fiber or combining the single-mode optical fiber with the strong-coupling multi-core optical fiber to serve as a main device in the RFL-based illumination light source, the generated RFL has multiple transvers modes and low spatial coherence which prevent speckle formation during illumination, which provides an ideal illumination light source for high-speed full-field speckle-free imaging technology.

The invention provides a laser projection device. An incident laser beam is expanded by a front fixed beam expander group, and then the incident laser beam then enters a zoom lens group; the zoom lensgroup selects the diameter of the expanded light beam and transmits the expanded light beam to a compensation lens group; the compensation lens group compensates the light output by the zoom lens group and outputs a collimated light beam; the collimated light beam passes through a focusing lens group to be converged at a rear focal plane of the focusing lens group; light beams diverged by a random phase plate positioned on the rear focal plane are collimated by a rear fixed collimating lens group to enter a fixed collimating lens group, and expanded collimated light beams are output through the rear fixed collimating lens group. According to the laser projection device provided by the invention, the refocused light beams after beam expansion can be gathered into a smaller focus which canbe approximately regarded as a standard focus of a rear collimating lens group, the random phase plate is placed at the position of the focus point to play the roles of dodging and speckle elimination, and so the continuous zoom beam expansion, collimation, dodging and speckle elimination are realized.

The invention discloses a laser light source device, a projection system and a control method of the projection system. According to the device, a laser beam is coupled into a multimode optical fiberfor transmission by adopting an optical coupling component, and the laser beam passing through the multimode optical fiber can generate random propagation time change, so that the time coherence of the laser is destroyed; then the laser beam passing through the multimode optical fiber enters an electro-refractive index changing component again, and a control signal is applied to the electro-refractive index changing component, so that the refractive index of a medium at the incident position of the laser beam is changed, and a spatial phase difference is generated at different positions by a light spot when the laser is emitted so as to reduce the spatial coherence of the laser; and the laser beam passing through the electro-refractive index changing component is incident to a light homogenizing component to further homogenize the laser beam. According to the laser light source device provided by the embodiment of the invention, the time and space coherence of the laser can be reducedat the same time, and speckles generated by the laser are effectively inhibited.

The invention relates to a white solid-state laser, which is particularly suitable for laser lighting, laser display and laser glaring. The white solid-state laser consists of a semiconductor laser array, a laser crystal, a nonlinear crystal and an optical system; a resonant cavity of fundamental frequency light is formed by the laser crystal and the nonlinear crystal; a first end face of the laser crystal and a second end face of the nonlinear crystal are directly plated with a film system to respectively form cavity mirrors of the resonant cavity of the fundamental frequency light; a periodically polarized nonlinear crystal is adopted by the nonlinear crystal; a one-dimensional linear array is adopted by the semiconductor laser array; and a red, green and blue laser synthesis system is adopted by the optical system for synthesizing three kinds of frequency doubling light into a white light beam and outputting the white light beam. The white solid-state laser has the advantages that the structure is compact, and miniaturization and mass production can be easily realized; the pump coupling efficiency and the optical conversion efficiency are high; the laser output power is stable, and the noise is low; the quality of the light beam is high, and the spatial coherence is low; the resonant cavity can be easily adjusted, the scope of the working temperature is wide, and the white solid-state laser can work reliably in a poor environment; and the service life of the laser is long.

A speckle reduction apparatus (300) based on Mie scattering and perturbation drive is disclosed. The speckle reduction apparatus (300) comprises an optical reflective chamber (302) having an incident-light coupling device (301) and an exiting face (303) disposed thereon, and an optical device (308) which faces the incident-light coupling device (301) of the optical reflective chamber (302). The inner walls of the optical reflective chamber (302), except for the wall of light transparent exiting face (303), are mirror surfaces. The optical reflective chamber (302) is fully filled with transparent material (401) having medium particles (402) dispersed therein, which are able to induce Mie scattering of the incident laser. Either or both of the optical reflective chamber (302) and the optical device (308) are provided with a perturbation-sensitive device. The present invention may be implemented with reasonable and compact structure, achieving the following effects: low cost, effective speckle reduction, high laser efficiency, stability, safety, and uniform light intensity.

The invention discloses a laser projector and method. The projector comprises a first laser unit which is provided with a first color laser, a first Cassegrain optical unit which is arranged on the output side of a first excitation light source unit and used for converting the non-parallel light beams output by the first laser unit into parallel light beams, a second laser unit having a second color laser, and a second Cassegrain optical unit which is arranged on the output side of a second excitation light source unit and used for converting the non-parallel light beams output by the second laser unit into parallel light beams. The laser projector provided by the invention has the advantages that the first Cassegrain optical unit (second Cassegrain optical unit) is used for shaping the first laser unit (second laser unit), and parallel light with a certain size of light spots is formed.