35results 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.

Methods for employing coherent bundles of optical fibers, whether single- or multi-mode, for optical coherence tomography or optical coherence microscopy. Either a substantially monochromatic source or a broadband source is spatially decohered and / or spatially filtered prior to coupling into the fiber bundle for illumination of a sample. A scatter signal from features disposed beneath the surface of the sample is interfered with a reference signal derived, at either end of the fiber bundle, from the identical source of illumination.

A source grating for X-rays and the like which can enhance spatial coherence and is used for X-ray phase contrast imaging is provided. The source grating for X-rays is disposed between an X-ray source and a test object and is used for X-ray phase contrast imaging. The source grating for X-rays includes a plurality of sub-gratings formed by periodically arranging projection parts each having a thickness shielding an X-ray at constant intervals. The plurality of sub-gratings are stacked in layers by being shifted.

A source grating for X-rays and the like which can enhance spatial coherence and is used for X-ray phase contrast imaging is provided. The source grating for X-rays is disposed between an X-ray source and a test object and is used for X-ray phase contrast imaging. The source grating for X-rays includes a plurality of sub-gratings formed by periodically arranging projection parts each having a thickness shielding an X-ray at constant intervals. The plurality of sub-gratings are stacked in layers by being shifted.

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.

Methods for employing coherent bundles of optical fibers, whether single- or multi-mode, for optical coherence tomography or optical coherence microscopy. Either a substantially monochromatic source or a broadband source is spatially decohered and / or spatially filtered prior to coupling into the fiber bundle for illumination of a sample. A scatter signal from features disposed beneath the surface of the sample is interfered with a reference signal derived, at either end of the fiber bundle, from the identical source of illumination.

A frequency-scanning interferometer is modified to include a diffuse reference surface. An illuminating system produces an expanding measuring beam, portions of which reflect from a test object surface and the diffuse reference surface on converging paths to an imaging system. Interference patterns between overlapping images of the object and reference surfaces are generated at a plurality of frequencies for measuring the object surface with respect to the reference surface.

The invention relates to a coaxial Fizeau synchronous phase shifting interferometer capable of adjusting extended light illumination and belongs to the field of an optical interference measuring device. The coaxial Fizeau synchronous phase shifting interferometer comprises an extended light source assembly, a fronting Michelson type interferometer assembly and a Fizeau main interferometer. In the invention, the fronting interferometer assembly is adopted to generate two illumination light waves of orthogonal polarization state; polarization phase shifting interferometry between a measured surface and a reference surface is realized through match of spatial coherence of the fronting interferometer and the main interferometer; and an additional fringe is removed by using the characteristic of a short coherent optical length of an extended light source space. The coaxial Fizeau synchronous phase shifting interferometer has the characteristics of long measuring distance, continuous and adjustable contrast ratio, continuous and adjustable coherent optical length, easy operation, lower error requirement on a high frequency surface shape of the reference surface and the like; and the coaxial Fizeau synchronous phase shifting interferometer can be used in the fields of high precision detection of an optical element, optical element on-line detection and super-smooth surface detection and the like.

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.

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 light homogenizing device and display equipment. The light homogenizing device comprises a first speckle eliminating assembly, a second speckle eliminating assembly and a third speckle eliminating assembly which are sequentially arranged along a light path, wherein the first speckle eliminating assembly comprises a first speckle eliminating piece and is used for diffusing a light beam entering the first speckle eliminating piece to form a first divergent light beam; the second speckle eliminating assembly comprises a second speckle eliminating piece and an electromagnetic vibration piece, the electromagnetic vibration piece is connected with the second speckle eliminating piece and used for controlling the second speckle eliminating piece to vibrate, and the second speckle eliminating piece is used for receiving the first divergent light beam and diffusing the first divergent light beam to form a second divergent light beam; and the third speckle eliminating assembly comprises a third speckle eliminating piece and a driving piece used for driving the third speckle eliminating piece to axially rotate, and the third speckle eliminating piece is used for receiving the second divergent light beam and emitting the second divergent light beam after the second divergent light beam is diffused. According to the technical scheme, the speckle effect of laser can be effectively reduced, and the light beam homogenization effect is achieved.

The present disclosure relates more particularly to active optical fibers, amplified spontaneous emission (ASE) sources using such active optical fibers, and imaging and detection systems and methods using such ASE sources. In one aspect, the disclosure provides an active optical fiber that includes a rare earth-doped gain core configured to emit radiation at at least a peak wavelength emitted wavelength when pumped with pump radiation having a pump wavelength; a pump core surrounding the gain core; and a cladding surrounding the pump core, wherein the value M=16R2(NA)2 / λ2 in which R is the gain core radius, NA is the active optical fiber numerical aperture, and λ is the peak emitted wavelength, is at least 50, or at least 100. The present disclosure also provides an optical source that includes the optical fiber coupled to a pump source.

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.

A speckle laser device based on low time coherence and low spatial coherence, and a preparation method therefor. The speckle laser device comprises a radio frequency modulator (1), a laser device (2), a diffracting optical element (3) and a focusing lens (4) that are coaxially and sequentially disposed on a same optical platform. The diffracting optical element (3) is located in the emergent direction of the laser device (2), the radio frequency modulator (1) modulates the laser device (2), and laser (001) modulated by the radio frequency modulator (1) enters the diffracting optical element (3). Laser beams emerging from the diffracting optical element (3) are zero-coherent speckle laser beams (002), the laser beams (002) enter the focusing lens (4), and the laser emerging from the focusing lens (4) forms a focused speckle laser (003). Speckle laser output beams are obtained by using a time coherence and spatial coherence reduction technology, and the problem of speckle production due to time coherence and spatial coherence is resolved.

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.

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.

An ultraviolet laser apparatus according to the present invention comprises a laser generating portion having a single-wavelength oscillating laser for generating laser light having a single wavelength falling within a wavelength range from an infrared band to a visible band, an optical amplifier having a fiber optical amplifier for amplifying the laser light generated by the laser generating portion, and a wavelength converting portion for wavelength-converting the amplified laser light into ultraviolet light by using a non-linear optical crystal, whereby ultraviolet light having a single wavelength is generated. Further, an exposure apparatus according to the present invention serves to transfer a pattern image of a mask onto a substrate and comprises a light source including a laser apparatus for emitting a laser light having a single wavelength, a first fiber optical amplifier for amplifying the laser light, a light dividing device for dividing or branching the amplified laser light into plural lights, and second fiber optical amplifiers for amplifying the plural divided or branched lights, respectively: and a transmission optical system for transmitting the laser light emitted from the light source to the exposure apparatus.

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 is applicable to the field of optics, and provides a laser output device and a laser ablation system. The laser output device comprises a laser and a coupling module which are connected in sequence; the laser is used for generating an initial light beam emitted to the coupling module, and the initial light beam is a light beam conforming to Gaussian energy distribution; the coupling module comprises a laser beam shrinking module, a homogenizing module and a focusing coupling module which are connected in sequence, and is used for converting the initial light beam into a target light beam and coupling the target light beam to the guide pipe, and the target light beam is a light beam with uniform energy distribution. According to the embodiment of the invention, the energy of the laser beams reaching the catheter can be homogenized, the spatial coherence of the beams is reduced, the situation that the energy of the laser is transversely redistributed to burn out the catheter is avoided, the energy loss of the output laser is also reduced, and the energy conversion rate of the laser is improved, so that the plaque ablation speed of laser ablation is increased.

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 relates to a coaxial Fizeau synchronous phase shifting interferometer capable of adjusting extended light illumination and belongs to the field of an optical interference measuring device. The coaxial Fizeau synchronous phase shifting interferometer comprises an extended light source assembly, a fronting Michelson type interferometer assembly and a Fizeau main interferometer. In the invention, the fronting interferometer assembly is adopted to generate two illumination light waves of orthogonal polarization state; polarization phase shifting interferometry between a measured surface and a reference surface is realized through match of spatial coherence of the fronting interferometer and the main interferometer; and an additional fringe is removed by using the characteristic of a short coherent optical length of an extended light source space. The coaxial Fizeau synchronous phase shifting interferometer has the characteristics of long measuring distance, continuous and adjustable contrast ratio, continuous and adjustable coherent optical length, easy operation, lower error requirement on a high frequency surface shape of the reference surface and the like; and the coaxial Fizeau synchronous phase shifting interferometer can be used in the fields of high precision detection of an optical element, optical element on-line detection and super-smooth surface detection and the like.