33results about How to "Speckle suppression" patented technology

The invention provides a method and device for designing a diffractive optical element. The method comprises the steps of S1, superposing the image light field complex amplitude of an image to be diffracted at a preset distance and the partially coherent light field of a partially coherent light source to obtain the interference complex amplitude; S2, substituting the light intensity of the partially coherent light field into the phase of the interference complex amplitude to obtain the diffractive complex amplitude; and S3, enabling the phase of the diffractive complex amplitude to serve as the transmittance to design the diffractive optical element. According to the method and device provided by the invention for designing the diffractive optical element, the characteristics that the coherent part of the partially coherent light can be coded and modulated and a non-coherent part of the partially coherent light can be averagely speckled are applied to the field of diffractive opticalelement design, a phenomenon of random rise and elimination of the light field amplitude is weakened while wavefront modulation is achieved, the speckles are suppressed, and the image quality is enhanced.

A method and an apparatus print a pattern of periodic features into a photosensitive layer. The methods includes the steps of: providing a substrate bearing the layer, providing a mask, arranging the substrate such that the mask has a tilt angle with respect to the substrate in a first plane orthogonal thereto, and providing collimated light for illuminating the mask pattern so as to generate a transmitted light-field composed of a range of transversal intensity distributions between Talbot planes separated by a Talbot distance so that the transmitted light-field has an intensity envelope in the first plane. The mask is illuminated with the light while displacing the substrate relative to the mask in a direction parallel to the first plane and to the substrate. The tilt angle and the intensity envelope are arranged so that the layer is exposed to an average of the range of transversal intensity distributions.

The invention discloses a projection screen and an ultra-short-focus projection system. The projection screen receives image light beams emitted by a projection device, and comprises a reflecting layer, a lens layer, an isolation layer and a scattering layer, wherein the isolation layer is arranged between the scattering layer and the lens layer; the image light beams pass through the scattering layer, the isolation layer and the lens layer in sequence and reach the reflecting layer after being emitted from the projection device; and after being reflected by the reflecting layer, the image light beams pass through the lens layer, the isolation layer and the scattering layer again and then, enter the human eyes. The ultra-short-focus projection system comprises the ultra-short-focus projection device and the projection screen. Laser generated by the ultra-short-focus projection device is projected onto the projection screen to form an image on the projection screen. The projection screen and the ultra-short-focus projection system can obviously reduce speckles of the projection screen.

The invention discloses a chaotic modulation speckle-free laser projector, which includes several groups of laser arrays, laser array driving devices, laser output parts and projection units, each group of laser arrays is composed of a plurality of same-color lasers; each group of laser arrays is followed by There are respective converging lenses and collimating lenses arranged along the respective optical paths, and laser output parts and projection units are arranged behind all the collimating lenses; the laser array driving device includes a chaotic electric signal generating device and a laser driving circuit, and the chaotic electric signal The output end of the generating device is connected to the input end of the broadband amplifier, the output of the broadband amplifier is to the bias device, the output of the laser driving circuit is to the bias device, and the bias device drives each group of multiple laser arrays through a line with a delay greater than 0.3 ns or greater than 6 cm. A laser glows. The invention ensures the full power output of the laser, not only suppresses the speckles of the laser, but also makes the projection effect of the projector better.

The invention relates to the semiconductor laser technology field and especially relates to a laser light source system and a display apparatus. A laser, a heat sink and a uniform light device are included. The laser comprises N laser chips and the N is an integer which is greater than or equal to 1. The N laser chips are arranged on the heat sink. In the heat sink, thermal conductivities of positions where at least two laser chips are located are different so that the laser chips at different positions possess a temperature difference and wavelengths of output light of the laser chips are changed. Laser beams emitted by the N laser chips are entered into the uniform light device. Through the uniform light device, the laser beams with different wavelength are superposed and finally laser beams which are uniformly distributed are acquired so that laser coherence is reduced and laser speckles are effectively restrained. The structure of the laser light source system is simple, cost is low and the system is easy to realize.

The present application discloses a laser speckle suppressing element and a suppressing method, which are used to improve the efficiency of speckle suppression and enhance the effect of speckle suppression. The element adopts a light-transmitting material; it includes an array composed of a plurality of light-transmitting regions; wherein, the lateral size of the light-transmitting regions is smaller than the spatial resolution of the human eye, and the difference in the longitudinal dimensions of adjacent light-transmitting regions makes the transmission of adjacent light-transmitting regions The optical path difference of the laser beams in the light area is not less than the coherence length of the laser beams. In this way, the time coherence between adjacent sub-laser beams can be destroyed, and the spatial coherence of the laser can be destroyed, so that adjacent sub-laser beams become The non-correlated light is obtained, so that the spatial superposition of multiple independent speckles can be realized within the resolution of the human eye, and the effective suppression of speckle can be realized.

The invention discloses a radar image speckle noise suppression method based on a correlation loss convolutional neural network, comprising: inputting a radar image into a trained convolutional neural network to obtain a result image suppressing speckle noise; a training method of the convolutional neural network It includes: superimposing speckle noise on the remote sensing image to obtain the superimposed speckle noise image, inputting the superimposed speckle noise image into the convolutional neural network, and obtaining the training output image; according to the mean square error of the remote sensing image and the training output image, the error loss is obtained , use the cross-correlation coefficient between the remote sensing image and the training output image to obtain the correlation loss; use the error loss and the correlation loss to perform backpropagation to update the weight parameters of the convolutional neural network; and then obtain the trained convolutional neural network. The invention utilizes the error loss and the correlation loss to update the weight parameter of the convolutional neural network, thereby effectively improving the radar image speckle noise suppression effect of the network.

The invention provides a static laser speckle reduction method combining a multimode optical waveguide and a diffractive optical device. The method comprises the following steps that Step 1, a laser beam is collimated and then input into the diffractive optical device, the diffractive optical device outputs the incident collimated laser beam as diffraction beams with different diffraction orders;Step 2, the diffraction beams with the different diffraction orders are focused by a lens, the focused beams are input into the multimode optical waveguide, the multimode optical waveguide modulates the transmission delay of different diffracted beams, so that the diffraction beams of all diffraction orders are output from the multimode optical waveguide at the delay difference delta T; Step 3, the diffraction beams output at different delays are collected by an imaging lens and imaged on a projection screen, the projection screen is provided with a rough surface, an image on the projection screen is received and processed by a digital camera, and the static laser speckle suppression is achieved. The static laser speckle reduction method combining the multimode optical waveguide and the diffractive optical device has the advantages that the reliability is high, electric energy supply is not needed, the response time is short, no mechanical running mechanism is needed, the system is simple, the size is small, and the cost is low.

To provide an illumination device and a projection type image display device that illuminate an area to be illuminated (image formation area) under conditions where speckle noise is less noticeable.An illumination device according to the present invention includes: a light source 11 that emits coherent light; an optical scanning section 15 that scans the coherent light emitted from the light source 11; and an optical path conversion system 21 configured to allow the coherent light scanned by the optical scanning section 15 to illuminate an area to be illuminated sequentially in an overlapping manner. An incident angle of the coherent light that enters respective points of the area to be illuminated changes with time.

The invention discloses a laser light source device, a projection system and a control method thereof. Optical coupling components are used to couple a laser beam to a multi-mode fiber for transmission. The laser beam passing through the multi-mode fiber will produce random propagation time changes, thereby destroying the laser beam. temporal coherence. Then, the laser beam passing through the multimode fiber is re-incident to the electro-refractive index changing component, and by applying a control signal to the electro-refractive index changing component, the refractive index of the medium at the incident position of the laser beam is changed, so that the light spot when the laser exits is changed. Spatial phase differences are created at different locations, thereby reducing the spatial coherence of the laser light. The laser beam passing through the electro-refractive index changing part is incident on the homogenizing part, so that the laser beam can be further homogenized. It can be seen that the above-mentioned laser light source device provided by the embodiment of the present invention can reduce the temporal and spatial coherence of the laser light at the same time, and effectively suppress the speckle generated by the laser light.

A device for realizing holographic microscopic imaging, the device includes an inverted microscope and a holographic imaging device, wherein: the inverted microscope has an optical path entrance and an optical path exit, and the object to be observed is illuminated by a linearly polarized laser bright field, carrying the information of the object to be observed The light enters the inverted microscope through the optical path entrance, and the magnified holographic image of the object is obtained in the inverted microscope. The optical path exit of the inverted microscope is connected with the optical path entrance of the holographic imaging device; The transverse modes and polarization of the field are coupled and compounded for measurement. The quantitative phase imaging implementation device proposed by the present invention uses an imaging method of non-labeled specimens, which does not cause photobleaching of molecular structures due to light absorption caused by fluorescence imaging, overcomes the toxicity of excitation light to biological cells, and makes the present invention applicable to Watch the evolution of living cells.

Disclosed is a highly adhesive polyester film for optical use, wherein the formation of an iris-like color pattern under the light of a fluorescent lamp is suppressed. The highly adhesive polyester film for optical use has excellent adhesion to a hard coat layer, excellent adhesion under high temperature, high humidity conditions (wet heat resistance), and chipping resistance of a coating layer. Specifically disclosed is a highly adhesive polyester film for optical use, wherein a coating layer containing a polyester resin, particles A and particles B is provided on at least one surface of a polyester film. The polyester resin contains, as acid components, a naphthalene dicarboxylic acid and a dicarboxylic acid component represented by formula (1) and / or a diol component represented by formula (2); the particles A are metal oxide particles having a refractive index of not less than 1.7 but not more than 3.0; and the particles B have an average particle diameter of not less than 200 nm but not more than 700 nm. (1) HOOC-(CH2)n-COOH (In the formula, n represents an integer satisfying 4 = n = 10.) (2) HO-(CH2)n-OH (In the formula, n represents an integer satisfying 4 = n = 10.)