| Speckle interferometry can be used to detected the object in a non-contact way in a whole field.After processing the speckle,the out of plane displacement information and in-plane displacement information can be obtained through image processing.The optical detection technology based on speckle interference has the characteristics of full field detection,no damage to the object to be measured and high resolution,which makes it widely used in non-destruction detection,strain detection,thermal deformation and other fields.In the engineering application,it is found that the components of speckle interference processing will limit the field of view of the system,especially the shearing speckle interference system,which will the area of a full field detection.The multifunctional digital speckle interference detection device has a light splitting prism,which limits the field of view of the speckle interference system.And the existence of the interference device will extend the back focus length of the optical system and limit the selection of the lens.On the premise that the imaging equipment in the multi-functional digital speckle detection device can meet the requirements of speckle interference and shearing speckle interference at the same time,an integrated dual-purpose mirror head which can increase the whole field detection once and can be used for speckle interference imaging and shearing speckle interference imaging is designed.The imaging equipment can collect the speckle pattern on the surface to be measured with a working distance of1.5m and an area of 1m × 1m.In the back focus length,a spectroprism can be introduced to divide the optical path into the shearing speckle interference optical path and the speckle interference optical path.Then there is the Michelson structure to realize the shearing speckle interference and the structure to realize the speckle interference leading into the reference light.The main contents of this paper:1.The investigation of the current research situation of speckle interferometry technology,and the way to increase the whole field detection;On the basic of the principle of speckle interference and shearing speckle interference with fully understanding,the influence of the relevant devices used for interference on the imaging field of view is analyzed,and the design of the optical path of the beam splitting and interference structure is designed;2.Based on the optical design index required by the project,the imaging principle of the retrofocus objective is analyzed,and the existing aberration and balance mode are discussed in combination with the imaging characteristics of the multi-functional digital speckle interference detection device.Using ZEMAX optical design software to select the appropriate initial structure according to the requirements of the project,and combining the optical design index of the project to set the basic parameters to design the imaging optical system of the multi-functional digital speckle interference detection device.In order to meet the project requirements,the optical path correction aberration is optimized,and the optical path is analyzed combined with image quality evaluation,and the corresponding tolerance analysis is carried out;3.Based on the analysis of the theory of optical machine design,the integrated structure of the anti telephoto objective and the interference module is designed.The stray light of the whole imaging interference system is analyzed by Trace Pro.Finally,designing a retrofocus imaging objective with large field of view and large inverted telephoto ratio.The effective focal length of the system is 16.8mm,the relative aperture is 1/3.44,and the maximum distortion is 1%.The MTF value at 104.2lp/mm reached 0.73.The imaging quality of the optical system is good and meets the requirements of the project. |
PDF Full Text Request