Spatial Light Modulation Scanning Optical Imaging

Generally,optical imaging in a scattering environment will result in poor visibility image quality due to light scattering in the transmission medium and signal attenuation.In order to improve the imaging quality,this paper designs a synchronously controlled scanning active illumination imaging system based on a mechanical spatial light modulator,which uses narrow beam illumination and narrow viewing angle to scan in sub-regions,and finally combines into a complete image.According to the overall design of the imaging system,determine the selection of hardware,complete the design and implementation of the system software,and finally complete the construction of the system.Although the synchronous scanning imaging method has a narrow viewing angle and single-pixel reception,it has the advantages of good anti-scattering performance and low cost.In order to filter out multiply scattered light to improve the de-scattering performance of the system and realize optical scanning imaging,a scanning galvanometer is used as the transmitter of the system to change the emission angle of the laser beam,and a mechanical spatial light modulator combined with a photodetector is used as the system receiver.Synchronized control scanning of the end of the active illumination imaging scheme.A mechanical spatial light modulator is placed on the imaging surface behind the optical lens to perform point-by-point,line-by-line,and column-by-column scanning.According to the requirements of the imaging scheme,the overlapping area of scanning is calculated,and the optical path detection model is established.Using perspective projection algorithm to design,determine the pixel area of the image plane where the mechanical spatial light modulator is located,select the pixels where the scanning path of each laser beam scans the target point and the imaging line coincident to pass through,while all other pixels are blocked,shield the scattered light as much as possible and improve the imaging performance of the system.On the basis of the existing liquid crystal spatial light modulator scanning imaging,a mechanical spatial light modulator with high transmittance is used to perform scanning twodimensional target grayscale imaging and anti-scattering performance experiments.In addition,the image contrast of scanning imaging with narrow beam illumination and narrow viewing angle reception and staring imaging with wide beam illumination and wide viewing angle reception is also analyzed and compared.The establishment of a new optical scanning imaging mechanism can greatly expand the selectable range of imaging devices to achieve better imaging results.The experimental results show that the system has good imaging performance and anti-scattering effect,and achieves the expected design purpose.