CN102103270A - Laser beam light balancing and shaping and speckle eliminating integrated device - Google Patents

Abstract

Translated fromChinese

本发明提供了一种激光光束匀光整形与消散斑一体化装置，属于激光显示和照明领域，尤其涉及激光投影显示和红外激光夜视领域。该装置将光束匀光整形与消散斑统一考虑，采用旋转全息散射器实现消散斑，采用纯相位衍射器件实现匀光整形，通过机械框架将全息散射器件、微型直流电机、纯相位衍射器件及傅里叶变换透镜连接固定成一个结构紧凑的整体，达到同时实现光束匀光整形与消散斑的目的。其中的全息散射器件和纯相位衍射器件均为薄片形衍射光学器件，体积小、轻薄，易于实现光机电集成与小型化；而且通过设计并采用双折射材料加工制作可使其具有保偏性能、充分利用激光本身固有的线偏振特性，进一步提高光能利用率。

The invention provides an integrated device for uniform light shaping and dispersing speckle of a laser beam, which belongs to the field of laser display and lighting, and in particular relates to the fields of laser projection display and infrared laser night vision. The device considers beam homogenization shaping and dispersing speckle uniformly, adopts rotating holographic diffuser to realize dispersing speckle, and uses pure phase diffraction device to realize uniform light shaping, and integrates holographic scattering device, micro DC motor, pure phase diffraction device and The Liye transformation lens is connected and fixed into a compact whole, so as to achieve the purpose of uniform beam shaping and dispersing speckle at the same time. Among them, the holographic scattering device and the pure phase diffraction device are both flake-shaped diffractive optical devices, which are small in size, light and thin, and easy to realize opto-mechanical integration and miniaturization; and through design and fabrication of birefringent materials, they can have polarization maintaining performance, Make full use of the inherent linear polarization characteristics of the laser itself to further improve the utilization rate of light energy.

Description

Translated fromChinese

激光光束匀光整形与消散斑一体化装置Integrated device for uniform light shaping and speckle dissipation of laser beam

技术领域technical field

本发明涉及一种用于激光投影显示和激光照明、能够同时实现激光光束匀光整形与消散斑的一体化的装置，属于激光显示和照明领域。The invention relates to an integrated device used for laser projection display and laser lighting, capable of simultaneously realizing uniform light shaping of laser beams and dispersing spots, and belongs to the field of laser display and lighting.

背景技术Background technique

激光具有亮度高、单色性(相干性)与方向性好等特点，在科学研究、工程技术及工农业生产中具有十分重要和广泛的应用；激光投影显示和红外激光夜视是其中的两个重要应用领域。激光投影显示采用激光器替代现有投影显示系统中的传统光源(如超高压汞灯等)，具有亮度高、色域范围大、色纯度与饱和度高等优点，目前有关激光投影显示技术的研究方兴未艾，许多发达国家的研究单位和大型公司都在大力研发激光投影显示技术和装置。采用红外激光作为主动照明光源的红外激光夜视技术在军事、公安和安防等方面具有重要应用。激光投影显示和主动照明红外激光夜视都需要均匀化的激光束照明，为实现均匀化激光照明，需要解决两大难题：(一)是激光光束的匀光整形，就是把激光器出射的单模或多模高斯光束转换成特定形状(如矩形或方形)且强度尽量均匀的光束；(二)是尽量减少或消除因激光高单色性(相干性)由干涉和衍射形成的散斑和条纹。Laser has the characteristics of high brightness, monochromaticity (coherence) and good directionality. It is very important and widely used in scientific research, engineering technology and industrial and agricultural production; laser projection display and infrared laser night vision are two of them. an important field of application. Laser projection display uses lasers to replace traditional light sources (such as ultra-high pressure mercury lamps, etc.) in existing projection display systems. It has the advantages of high brightness, large color gamut, high color purity and saturation, etc. At present, the research on laser projection display technology is in the ascendant , research units and large companies in many developed countries are vigorously developing laser projection display technology and devices. Infrared laser night vision technology using infrared laser as active lighting source has important applications in military, public security and security. Both laser projection display and active lighting infrared laser night vision require uniform laser beam illumination. In order to achieve uniform laser illumination, two major problems need to be solved: (1) the uniform light shaping of the laser beam, which is the single-mode laser output Or a multi-mode Gaussian beam is converted into a beam of a specific shape (such as a rectangle or a square) and the intensity is as uniform as possible; (2) to minimize or eliminate the speckle and fringe formed by interference and diffraction due to the high monochromaticity (coherence) of the laser .

目前用于普通光源的光束匀光整形方法与装置是基于光线反射或折射原理的，主要有积分棒和透镜阵列两大类。目前市场上的投影仪和背投电视中大都采用这两种方法及相应装置。基于同样的原理，通过设计和工艺改进，有些研究单位或公司提出了用于激光光束匀光整形的方法和装置，如：中国专利CN1658054A公开的《激光匀光器》、中国专利CN201287242公开的《激光光束整形装置》、中国专利CN101377557公开的《激光匀光消相干装置》等。从原理上讲基于反射或折射原理的方法与装置对于激光光束也能起到一定的匀光整形作用，但由于它们对干涉和衍射效应考虑较少，所以当用于激光时还会产生一定的散斑和背景条纹；且一般来说该类装置的制作工艺复杂、体积较大，不利于光机电集成与小型化。Currently, beam uniformity shaping methods and devices used for ordinary light sources are based on the principle of light reflection or refraction, and mainly include integrating rods and lens arrays. These two methods and corresponding devices are mostly adopted in projectors and rear projection TVs currently on the market. Based on the same principle, through design and process improvement, some research units or companies have proposed methods and devices for laser beam homogenization and shaping, such as: "Laser Homogenizer" disclosed in Chinese Patent CN1658054A, "Laser Homogenizer" disclosed in Chinese Patent CN201287242 Laser Beam Shaping Device", Chinese Patent CN101377557 disclosed "Laser Uniform Light Decoherence Device", etc. In principle, methods and devices based on the principle of reflection or refraction can also play a certain role in uniform light shaping for laser beams, but because they have less consideration for interference and diffraction effects, they will also produce certain effects when used in laser beams. Speckle and background stripes; and generally speaking, the manufacturing process of this type of device is complicated and the volume is large, which is not conducive to opto-mechanical integration and miniaturization.

激光的相干性好，容易产生散斑和背景条纹，这是采用普通非相干光源时所没有的。有关降低或消除散斑和背景条纹的原理和方法，文献中已有多种论述，如：采用多波长激光或脉冲激光叠加等方法以降低时间相干性，采用激光器阵列、光纤束、旋转或振动散射体、振动光纤、振动屏幕或超声光栅等方法以降低空间相干性。中国专利CN201340489Y公开的《激光消散斑装置》采用电磁振动装置使光纤束产生随机振动；中国专利CN201387516Y公开号《一种消散斑装置及使用该消散斑装置的激光投影仪》中采用脉冲电源与逆压电材料体，使环绕在逆压电材料体上的光纤束产生无规伸缩；中国专利CN101425656公开的《一种减少激光散斑效应的方法》利用压电效应、电光效应、声光效应及标准具快速改变激光器腔长，使激光输出波长快速变化或跃变，从而达到降低激光的时间相干性、降低散斑效应的目的。此外，中国专利CN1727938A公开的《激光投影电视照明系统中的光束均匀化装置》采用衍射光学器件把扩束后的圆形或环形或椭圆形激光束转换为方形照明光束，经过对所用衍射光学器件进行特殊设计，该装置在实现光束整形的同时具有一定的匀光效果，但由于其中的器件是固定不动的，因此难以降低或消除系统中由其它器件所引起的散斑与条纹。The coherence of the laser is good, and it is easy to produce speckles and background stripes, which are not available when using ordinary incoherent light sources. There have been many discussions in the literature on the principles and methods of reducing or eliminating speckle and background stripes, such as: using multi-wavelength lasers or pulsed laser superposition to reduce time coherence, using laser arrays, fiber bundles, rotation or vibration Scatterers, vibrating fibers, vibrating screens, or ultrasonic gratings to reduce spatial coherence. Chinese Patent CN201340489Y discloses "Laser Speckle Dissipation Device" using an electromagnetic vibration device to generate random vibrations in the fiber bundle; Chinese Patent CN201387516Y Publication No. "A Speckle Dissipation Device and a Laser Projector Using the Speckle Dissipation Device" uses a pulse power supply and an inverter The piezoelectric material body makes the optical fiber bundle around the inverse piezoelectric material body produce random expansion and contraction; Chinese patent CN101425656 discloses "A Method for Reducing Laser Speckle Effect" by using piezoelectric effect, electro-optic effect, acousto-optic effect and The etalon rapidly changes the laser cavity length, so that the laser output wavelength changes or jumps rapidly, thereby achieving the purpose of reducing the temporal coherence of the laser and reducing the speckle effect. In addition, Chinese Patent CN1727938A disclosed "Beam Homogenization Device in Laser Projection TV Illumination System" adopts diffractive optical device to convert the expanded circular or circular or elliptical laser beam into a square illumination beam, after the diffractive optical device used With a special design, the device has a certain uniform light effect while realizing beam shaping, but because the components in it are fixed, it is difficult to reduce or eliminate the speckles and stripes caused by other components in the system.

纯相位衍射光学器件的设计基于光波干涉与衍射原理，其制作可采用光学微加工等工艺，具有体积小、效率高等特点，非常适合于光机电集成与小型化，已在许多领域获得重要应用，如光学折衍混合成像系统、光学检测、激光加工及激光显示等领域。近年来，纯相位衍射光学器件的设计理论、算法和制作工艺已比较成熟。当把纯相位衍射光学器件用于激光投影显示或红外激光夜视的照明系统中时，就该器件本身来说，可以获得较好的均匀照明效果，但系统中其它光学器件上的灰尘、划痕及前后表面的多次反射，仍然会造成较为明显的散斑与背景干涉衍射条纹，这将会严重影响视频图像的成像质量(如成像清晰度、图像分辨率等)，尤其是当采用三基色激光实现彩色显示或成像时，散斑和条纹的存在会形成无规则的颜色闪烁现象，不利于色域管理，造成画面色彩失真或变差，还容易造成人眼疲劳。The design of pure phase diffraction optical devices is based on the principle of light wave interference and diffraction. Its production can be made by optical micromachining and other processes. It has the characteristics of small size and high efficiency. It is very suitable for opto-mechanical integration and miniaturization, and has been used in many fields. Such as optical refraction-diffraction hybrid imaging system, optical detection, laser processing and laser display and other fields. In recent years, the design theory, algorithm and manufacturing process of pure phase diffractive optical devices have been relatively mature. When the pure phase diffraction optical device is used in the lighting system of laser projection display or infrared laser night vision, as far as the device itself is concerned, a better uniform lighting effect can be obtained, but dust, scratches on other optical devices in the system The multiple reflections on the front and rear surfaces will still cause relatively obvious speckle and background interference diffraction fringes, which will seriously affect the imaging quality of the video image (such as imaging clarity, image resolution, etc.), especially when using three When the primary color laser realizes color display or imaging, the existence of speckles and stripes will form irregular color flickering phenomenon, which is not conducive to color gamut management, resulting in distortion or deterioration of picture color, and easy to cause eye fatigue.

实现激光光束整形，并尽量降低或消除散斑和背景条纹，一直是激光投影显示及红外激光夜视等领域中的技术难题，也是限制其实用化的瓶颈之一。若能够将二者一体化、做到结构紧凑小型化，将具有更重要意义和实用价值。Realizing laser beam shaping and minimizing or eliminating speckles and background stripes has always been a technical problem in the fields of laser projection display and infrared laser night vision, and it is also one of the bottlenecks that limit its practicality. If the two can be integrated to achieve a compact and miniaturized structure, it will have more important significance and practical value.

发明内容Contents of the invention

本发明针对现有光束匀光整形与消散斑技术存在的不足，提供一种结构紧凑、集光束匀光整形与消散斑于一体的激光光束匀光整形与消散斑一体化装置。The invention aims at the deficiencies of the existing beam homogenization shaping and speckle dissipation technology, and provides a laser beam homogenization shaping and speckle dissipation integrated device with compact structure and integrating beam homogenization shaping and speckle dissipation.

本发明的激光光束匀光整形与消散斑一体化装置采用以下技术方案：The laser beam homogenization shaping and speckle dissipation integrated device of the present invention adopts the following technical solutions:

该激光光束匀光整形与消散斑一体化装置，包括机械框架、微型直流电机、全息散射器件、纯相位衍射器件和傅里叶变换透镜，微型直流电机固定在机械框架上，全息散射器件安装在微型直流电机上；纯相位衍射器件固定在机械框架上并位于全息散射器件的后方，傅里叶变换透镜固定在机械框架上并位于纯相位衍射器件的后方，纯相位衍射器件和傅里叶变换透镜的光轴与入射光束共轴，把全息散射器件与纯相位衍射器件通过机械框架固定连接在一起，将光束整形和消散斑集成为一体，入射光束入射到全息散射器件上，全息散射器件在微型直流电机的驱动下高速旋转实现对入射光束的散射并透射，使不相干的散射场在积分时间内随机高速叠加并在视觉上形成平均效果，达到降低或消除散斑与条纹的目的，从全息散射器件出射的光场入射到纯相位衍射器件上，经衍射与透射再入射到傅里叶变换透镜上，经纯相位衍射器件和傅里叶变换透镜共同作用，在傅里叶变换透镜的后焦面上形成所需形状的均匀化光斑。The laser beam homogenization shaping and speckle disappearing integrated device includes a mechanical frame, a micro DC motor, a holographic scattering device, a pure phase diffraction device and a Fourier transform lens. The micro DC motor is fixed on the mechanical frame, and the holographic scattering device is installed on the On a micro DC motor; the pure phase diffraction device is fixed on the mechanical frame and is located behind the holographic scattering device, the Fourier transform lens is fixed on the mechanical frame and is located at the rear of the pure phase diffraction device, the pure phase diffraction device and the Fourier transform The optical axis of the lens is coaxial with the incident beam, and the holographic scattering device and the pure phase diffraction device are fixedly connected together through a mechanical frame, and the beam shaping and dispersing spots are integrated. The incident beam is incident on the holographic scattering device, and the holographic scattering device is in the Driven by a micro-DC motor, it rotates at high speed to scatter and transmit the incident beam, so that the irrelevant scattered field is randomly superimposed at high speed during the integration time and forms an average effect visually, so as to reduce or eliminate speckles and stripes. The light field emitted by the holographic scattering device is incident on the pure phase diffraction device, and then incident on the Fourier transform lens after diffraction and transmission. A homogenized spot of desired shape is formed on the back focal plane.

机械框架是由前中后三个固定支撑板及连接支柱组成，三个固定支撑板上均设有一个中心开孔，三个中心开孔必须是共轴的，前固定支撑板上除有一个中心开孔外，还有一个偏心开孔，其中心开孔用于通过入射光束，偏心开孔用于安装固定微型直流电机，中间固定支撑板上的中心开孔用于安装固定纯相位衍射器件，后固定支撑板上的中心开孔用于安装固定傅里叶变换透镜。The mechanical frame is composed of three fixed support plates and connecting pillars at the front, middle and rear. There is a central opening on each of the three fixed support plates. The three central openings must be coaxial, except for one on the front fixed support plate. In addition to the central opening, there is also an eccentric opening, the central opening is used to pass the incident light beam, the eccentric opening is used to install and fix a micro DC motor, and the central opening on the middle fixed support plate is used to install a fixed pure phase diffraction device , the central opening on the rear fixed support plate is used for installing and fixing the Fourier transform lens.

微型直流电机安装固定时要保证其电机轴与机械框架的中心轴尽量平行，微型直流电机的电机轴与机械框架中心轴的最大夹角小于5度。When installing and fixing the micro DC motor, ensure that its motor shaft is as parallel as possible to the central axis of the mechanical frame, and the maximum angle between the motor shaft of the micro DC motor and the central axis of the mechanical frame is less than 5 degrees.

全息散射器件是一个依据光学全息原理设计、在硬质透明光学基底材料上用光学微加工工艺制作的圆片形器件，其表面刻蚀有多种微结构，散射角小于2度。The holographic scattering device is a disk-shaped device designed on the basis of the principle of optical holography and fabricated on a hard transparent optical substrate by optical micromachining. Its surface is etched with various microstructures, and the scattering angle is less than 2 degrees.

纯相位衍射器件是一个依据光波衍射原理设计、在硬质透明光学双折射基底材料上用光学微加工工艺制作的圆片形器件，其表面刻蚀有微结构，具有保偏功能。The pure phase diffraction device is a disk-shaped device designed based on the principle of light wave diffraction and fabricated on a hard transparent optical birefringent substrate material by optical micromachining technology. Its surface is etched with microstructures and has a polarization-maintaining function.

傅里叶变换透镜为凸透镜。The Fourier transform lens is a convex lens.

本发明将光束整形和消散斑统一考虑，不仅结构紧凑的、能同时实现光束匀光整形与消散斑的一体化，而且还可以充分利用激光本身所固有的线偏振特性，从而大大提高光能利用率，具有体积小、轻薄、易于复制及批量生产等优点，价格便宜、成本低的特点，非常适合于光机电集成与小型化。The invention considers beam shaping and dispersing speckle uniformly, not only has a compact structure, can realize the integration of beam homogenization shaping and dispersing speckle at the same time, but also can make full use of the inherent linear polarization characteristics of the laser itself, thereby greatly improving the utilization of light energy It has the advantages of small size, light and thin, easy to copy and mass production, low price and low cost, and is very suitable for opto-mechanical integration and miniaturization.

附图说明Description of drawings

图1是本发明所述装置的结构示意图。Fig. 1 is a schematic structural view of the device of the present invention.

图2是本发明中机械框架的结构示意图。Fig. 2 is a structural schematic diagram of the mechanical frame in the present invention.

其中：1、机械框架，2、微型直流电机，3、全息散射器件，4、纯相位衍射器件，5、傅里叶变换透镜，6、偏心开孔，7、中心开孔，8、前固定支撑板，9、支柱，10、中间固定支撑板，11、后固定支撑板。Among them: 1. Mechanical frame, 2. Micro DC motor, 3. Holographic scattering device, 4. Pure phase diffraction device, 5. Fourier transform lens, 6. Eccentric opening, 7. Center opening, 8. Front fixation Support plate, 9, pillar, 10, middle fixed support plate, 11, rear fixed support plate.

具体实施方式Detailed ways

本发明激光光束匀光整形与消散斑一体化装置的整体结构如图1所示，主要包括用于连接和固定各个器件的机械框架1、微型直流电机2、全息散射器件3、纯相位衍射器件4和傅里叶变换透镜5。微型直流电机2固定在机械框架1上。全息散射器件3安装在微型直流电机上2，在微型直流电机2的驱动下高速旋转，用于消除散斑。纯相位衍射器件4固定在机械框架1上，并位于全息散射器件3的后方，用于光束匀光整形。傅里叶变换透镜5固定在机械框架1上，并位于纯相位衍射器件4的后方，可与纯相位衍射器件结合，在傅里叶变换透镜5的后焦面上产生特定形状的均匀化光斑。纯相位衍射器件4和傅里叶变换透镜5的中心线与入射光束的中心线为同一直线(即共轴)。The overall structure of the laser beam homogenization shaping and dispersing speckle integrated device of the present invention is shown in Figure 1, which mainly includes amechanical frame 1 for connecting and fixing various devices, a micro DC motor 2, aholographic scattering device 3, and a purephase diffraction device 4 and Fouriertransform lens 5. The micro DC motor 2 is fixed on themechanical frame 1 . Theholographic scattering device 3 is installed on the micro DC motor 2 and rotates at a high speed driven by the micro DC motor 2 to eliminate speckles. The purephase diffraction device 4 is fixed on themechanical frame 1 and is located behind theholographic scattering device 3 for beam homogenization and shaping. TheFourier transform lens 5 is fixed on themechanical frame 1 and is located behind the purephase diffraction device 4, which can be combined with the pure phase diffraction device to generate a uniform spot of a specific shape on the back focal plane of theFourier transform lens 5 . The centerlines of the purephase diffraction device 4 and theFourier transform lens 5 and the centerline of the incident light beam are on the same straight line (ie, coaxial).

机械框架1的结构如图2所示，包括前固定支撑板8、中间固定支撑板10、后固定支撑板11三个固定支撑板和四个支柱9，三个固定支撑板自前而后连接在四个支柱上。前固定支撑板8的设有一个中心开孔7，中心开孔7一侧设有一个偏心开孔6，入射激光束从中心开孔7进入，微型直流电机2固定在偏心开孔6上。中间固定支撑板10上设有一个中心开孔，用来固定纯相位衍射器件4。后面固定支撑板上设有一个中心开孔，用来固定傅里叶变换透镜5。机械框架1中的前中后三个固定支撑板上的中心开孔必须共轴的，即三个中心开孔的中心线为同一直线。The structure ofmechanical frame 1 is as shown in Figure 2, comprises front fixedsupport plate 8, middle fixedsupport plate 10, rear fixedsupport plate 11 three fixed support plates and fourpillars 9, three fixed support plates are connected on four sides from front to back. on a pillar. The front fixedsupport plate 8 is provided with acentral opening 7, and one side of thecentral opening 7 is provided with aneccentric opening 6, the incident laser beam enters from thecentral opening 7, and the micro DC motor 2 is fixed on theeccentric opening 6. A central opening is provided on the middle fixedsupport plate 10 for fixing the purephase diffraction device 4 . A central opening is arranged on the back fixed support plate for fixing theFourier transform lens 5 . The central openings on the front, middle and rear three fixed support plates in themechanical frame 1 must be coaxial, that is, the centerlines of the three central openings are the same straight line.

微型直流电机2可长时间高速旋转，转速在几百至几千转每秒之间可控，且振动和噪声低。安装固定时保证微型直流电机的电机轴与机械框架中心轴尽量平行，最大夹角要小于5度。The micro DC motor 2 can rotate at a high speed for a long time, the rotating speed is controllable between several hundred to several thousand revolutions per second, and the vibration and noise are low. When installing and fixing, ensure that the motor shaft of the micro DC motor is as parallel as possible to the central axis of the mechanical frame, and the maximum included angle is less than 5 degrees.

全息散射器件3是一个依据光学全息原理设计、在硬质透明光学基底材料上用光学微加工工艺制作的圆片形器件，其表面刻蚀有多种微结构，对光具有散射作用，散射角控制在2度之内；其中心设有用于固定在微型直流电机2的电机轴上的固定小孔。全息散射器在微电机驱动下高速旋转，达到降低或消除散斑与背景条纹的效果。制作全息散射器件3的基底材料可以根据具体应用中激光束的强弱选择不同的材质，如光学玻璃或聚合物塑料等。采用双折射材料作为基底，并经过设计与加工制作，可使全息散射器件3具有保偏功能。Holographic scattering device 3 is a disk-shaped device designed based on the principle of optical holography and fabricated on a hard transparent optical substrate by optical micromachining technology. Its surface is etched with various microstructures, which have a scattering effect on light. The scattering angle It is controlled within 2 degrees; its center is provided with a fixed hole for being fixed on the motor shaft of the micro DC motor 2. The holographic diffuser rotates at a high speed driven by a micro-motor to reduce or eliminate speckle and background stripes. The base material for making theholographic scattering device 3 can be made of different materials, such as optical glass or polymer plastic, etc., according to the strength of the laser beam in a specific application. Theholographic scattering device 3 can have a polarization-maintaining function by using a birefringent material as a substrate, and through design and fabrication.

纯相位衍射器件4是一个依据光波衍射原理设计、在硬质透明光学双折射基底材料上用光学微加工工艺制作的圆片形器件，其表面刻蚀有经特殊设计的微结构，可实现将圆形或椭圆形高斯或准高斯光束转换成正方形或矩形等多种形状的均匀化光束。纯相位衍射器件4的设计原理与算法在文献资料中已有很多论述，有多种，如基于傅立叶变换的迭代算法及其各种改进算法、基于搜索极值的优化算法、基于傅立叶变换迭代和搜索极值相结合的各种算法等。制作所述4纯相位衍射器件的基底材料可以根据具体应用中激光束的强弱选择不同的材质，如光学玻璃或聚合物塑料等。采用双折射材料作为基底，并经过设计与加工制作，可使纯相位衍射器件4具有保偏功能。The phase-onlydiffraction device 4 is a disk-shaped device designed on the basis of the principle of light wave diffraction and manufactured on a hard transparent optical birefringent substrate material by optical micromachining technology. Its surface is etched with a specially designed microstructure, which can realize the Circular or elliptical Gaussian or quasi-Gaussian beams are converted into homogenized beams of various shapes such as square or rectangular. The design principles and algorithms of the phase-onlydiffraction device 4 have been discussed in literature, and there are many kinds, such as the iterative algorithm based on Fourier transform and its various improved algorithms, the optimization algorithm based on searching for extremum, the iterative algorithm based on Fourier transform and Search for various algorithms for extremum combinations, etc. The base material for making the 4 pure phase diffraction devices can be made of different materials, such as optical glass or polymer plastic, etc., according to the intensity of the laser beam in specific applications. Using a birefringent material as a substrate, and through design and fabrication, the purephase diffraction device 4 can have a polarization maintaining function.

傅里叶变换透镜5为凸透镜，其焦距和孔径可根据具体应用要求而定，其主要作用是使经过纯相位衍射器件4的光束在其后焦面上形成所需形状的均匀化光斑。光斑的形状由纯相位衍射器件4的结构参数决定，光斑的大小由纯相位衍射器件4的参数及傅里叶变换透镜5的参数共同决定。由于傅里叶变换透镜5后焦面上的光场分布相当于衍射屏远场处的衍射光场分布，所以在某些应用场合如红外激光夜视系统中，可以省去所述装置中的傅里叶变换透镜。TheFourier transform lens 5 is a convex lens, its focal length and aperture can be determined according to specific application requirements, and its main function is to make the light beam passing through the purephase diffraction device 4 form a homogenized spot of required shape on its back focal plane. The shape of the light spot is determined by the structural parameters of the purephase diffraction device 4 , and the size of the light spot is jointly determined by the parameters of the purephase diffraction device 4 and the parameters of theFourier transform lens 5 . Since the light field distribution on the rear focal plane of theFourier transform lens 5 is equivalent to the diffraction light field distribution at the far field of the diffraction screen, in some applications such as infrared laser night vision systems, the device can be omitted. Fourier transform lens.

图中入射光束是来自激光器的待处理光束，可以是会聚或发散光束，也可以是经过准直的光束。来自激光器的入射光束从框架1的第一个固定支撑板上的中心孔入射，入射到全息散射器件3上，全息散射器件3实现对入射光束的散射并透射。全息散射器件3在微型直流电机2的驱动下高速旋转，使多个不相干的散射场在积分时间内随机高速叠加并在视觉上形成平均效果，达到降低或消除散斑与条纹的目的。从全息散射器件3出射的光场入射到纯相位衍射器件4上，经衍射与透射再入射到傅里叶变换透镜5上。经纯相位衍射器件4和傅里叶变换透镜5共同作用，在傅里叶变换透镜5的后焦面上形成所需形状的均匀化光斑。若不采用傅里叶变换透镜5，则可在远场处得到所需形状的均匀化光斑。所述装置的均匀化出射光束可以作为照明光束直接(或经过光学成像延迟系统)照明激光投影显示系统中的光调制器；也可作为红外激光夜视系统中的照明光束照明目标物，此时因目标物一般较远，一般可不用傅里叶变换透镜5。The incident beam in the figure is the beam to be processed from the laser, which can be a converging or diverging beam, or a collimated beam. The incident light beam from the laser is incident from the central hole on the first fixed support plate of theframe 1, and incident on theholographic scattering device 3, and theholographic scattering device 3 realizes scattering and transmission of the incident light beam. Theholographic scattering device 3 rotates at a high speed driven by the micro DC motor 2, so that multiple irrelevant scattering fields are randomly superimposed at high speed during the integration time and form an average effect visually, so as to reduce or eliminate speckles and stripes. The light field emitted from theholographic scattering device 3 is incident on the purephase diffraction device 4 , and then incident on theFourier transform lens 5 after diffraction and transmission. Through the joint action of the purephase diffraction device 4 and theFourier transform lens 5 , a homogenized light spot of required shape is formed on the back focal plane of theFourier transform lens 5 . If theFourier transform lens 5 is not used, a homogenized spot of desired shape can be obtained at the far field. The homogenized outgoing beam of the device can be used as an illumination beam to directly (or pass through an optical imaging delay system) illuminate the light modulator in the laser projection display system; it can also be used as an illumination beam in the infrared laser night vision system to illuminate the target, at this time Because the target object is generally far away, theFourier transform lens 5 can generally not be used.

图1中的出射光束在特定位置(如傅里叶变换透镜5的后焦面)上产生整形和消散斑后的均匀化光斑。在某些应用场合如红外激光夜视系统中，可以省去装置中的傅里叶变换透镜5。在彩色激光投影显示系统中，若三基色激光的光路是分离的，所述装置需要用于三基色激光光路的每一路。The outgoing light beam in FIG. 1 produces a homogenized light spot after shaping and dissipating the spot at a specific position (such as the back focal plane of the Fourier transform lens 5 ). In some applications such as infrared laser night vision systems, theFourier transform lens 5 in the device can be omitted. In a color laser projection display system, if the optical paths of the three primary color lasers are separated, the device needs to be used for each of the three primary color laser light paths.

本发明的装置，不仅结构紧凑的、能同时实现光束匀光整形与消散斑的一体化，而且还可以充分利用激光本身所固有的线偏振特性，从而大大提高光能利用率。传统光源如超高压汞灯或卤素灯发出的光多为非偏振光，而投影显示中的光调制器(如LCD或LCOS等)需要线偏振光照明，为了适应这一需求，传统投影显示系统中一般是在光路中采用多个线偏振器件，这必然会损失掉大量光能。而激光器出射的光一般为线偏振光，对于采用激光光源的投影显示系统，最好是直接且充分利用激光本身的线偏振特性，在系统中不用或尽量少用线偏振器件。The device of the present invention not only has a compact structure, can simultaneously realize the integration of light beam homogenization shaping and dispersing speckles, but also can fully utilize the inherent linear polarization characteristics of the laser itself, thereby greatly improving the utilization rate of light energy. The light emitted by traditional light sources such as ultra-high pressure mercury lamps or halogen lamps is mostly non-polarized light, while the light modulators (such as LCD or LCOS, etc.) in projection displays require linearly polarized light illumination. In order to meet this demand, traditional projection display systems In general, multiple linear polarization devices are used in the optical path, which will inevitably lose a lot of light energy. The light emitted by the laser is generally linearly polarized light. For a projection display system using a laser light source, it is best to directly and fully utilize the linear polarization characteristics of the laser itself, and not use or minimize the use of linear polarization devices in the system.

本发明的具有有益效果：The present invention has beneficial effects:

1.将光束整形和消散斑统一考虑，实现了匀光整形与消散斑一体化，可使光学系统结构更紧凑，有利于实现小型化及光机电集成化；1. Considering the beam shaping and dispersing speckle uniformly, the integration of uniform light shaping and dispersing speckle is realized, which can make the structure of the optical system more compact, which is conducive to the realization of miniaturization and opto-mechanical integration;

2.用于消散斑的全息散射器件和用于匀光整形的纯相位衍射器件，都是基于光波干涉衍射原理设计、采用光学微加工工艺制作，都是高度透明的衍射器件，衍射效率高，可提高系统的光能利用率；2. The holographic scattering device used for speckle dissipation and the pure phase diffraction device used for uniform light shaping are both designed based on the principle of light wave interference diffraction and manufactured by optical micromachining technology. They are highly transparent diffraction devices with high diffraction efficiency. It can improve the light energy utilization rate of the system;

3.用于消散斑的全息散射器件和用于匀光整形的纯相位衍射器件，若选取特殊的双折射基底材料、设计方法与参数，可制作成保偏器件，还可充分利用激光的线偏振特性从而进一步提高光能利用率。3. The holographic scattering device used for speckle dissipation and the pure phase diffraction device used for uniform light shaping can be made into polarization-maintaining devices if special birefringent substrate materials, design methods and parameters are selected, and the laser line can also be fully utilized. Polarization characteristics to further improve light energy utilization.

4.用于消散斑的全息散射器件和用于匀光整形的纯相位型衍射器件，具有体积小、轻薄、易于复制及批量生产等优点，价格便宜、成本低。4. The holographic scattering device for dispersing speckle and the pure phase diffraction device for uniform light shaping have the advantages of small size, thinness, easy replication and mass production, etc., and are cheap and low in cost.

5.可广泛应用于如激光投影显示、红外激光夜视及需要激光照明的其它领域。5. It can be widely used in laser projection display, infrared laser night vision and other fields that require laser lighting.

Claims (5)

1. a laser beam is spared polishing shape and dissipation spot integrated apparatus, comprise mechanical framework, DC micromotor, holographic diffuser part, pure phase position diffractive optical element and Fourier transform lens, it is characterized in that: DC micromotor is fixed on the mechanical framework, and the holographic diffuser part is installed on the DC micromotor; Pure phase position diffractive optical element is fixed on the mechanical framework and is positioned at the rear of holographic diffuser part, Fourier transform lens is fixed on the mechanical framework and is positioned at the rear of pure phase position diffractive optical element, the optical axis and the incident beam of pure phase position diffractive optical element and Fourier transform lens are coaxial, holographic diffuser part and pure phase position diffractive optical element are fixed together by mechanical framework, beam shaping and dissipation spot are become one, incident beam incides on the holographic diffuser part, holographic diffuser part high speed rotating under the driving of DC micromotor is realized scattering and the transmission to incident beam, incoherent scattered field is superposeed at a high speed in integral time at random also visually form average effect, reach the purpose that reduces or eliminate speckle and striped, incide on the diffractive optical element of pure phase position from the light field of holographic diffuser part outgoing, reenter through diffraction and transmission and to be mapped on the Fourier transform lens, through pure phase position diffractive optical element and Fourier transform lens acting in conjunction, on the back focal plane of Fourier transform lens, form the homogenising hot spot of required form.

2. even polishing shape of laser beam according to claim 1 and dissipation spot integrated apparatus, it is characterized in that: described mechanical framework is made up of back three fixed support plates and connecting struts in preceding, be equipped with a center drilling on three fixed support plates, three center drillings must be coaxial, before on the fixed support plate except that a center drilling is arranged, also has an offset hole, its center drilling is used to pass through incident beam, offset hole is used to install and fix DC micromotor, center drilling on the center fixed back up pad is used to install and fix pure phase position diffractive optical element, and the center drilling on the back fixed support plate is used to install and fix Fourier transform lens.

3. even polishing shape of laser beam according to claim 1 and dissipation spot integrated apparatus, it is characterized in that: described holographic diffuser part is a disc device of using the making of optics micro fabrication according to the optical holography principle design, on hard transparent optical substrate material, its surface etch has multiple microstructure, and scattering angle is less than 2 degree.

4. even polishing shape of laser beam according to claim 1 and dissipation spot integrated apparatus, it is characterized in that: described pure phase position diffractive optical element is a disc device that designs, makes of the optics micro fabrication on hard transparent optical birefringence base material according to the light wave diffraction principle, its surface etch has microstructure, has the inclined to one side function of guarantor.

5. even polishing shape of laser beam according to claim 1 and dissipation spot integrated apparatus is characterized in that: the angle of the motor shaft of described DC micromotor and mechanical framework central shaft is less than 5 degree.

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