Study Of Optical Testing Of Cylindrical Surface With Computer Generated-Hologram

The cylindrical surface has been widely used in optical beam shaping systems, due toits different focal power in two perpendicular directions. In recent years, with the rapiddevelopment of high-power laser devices, synchrotron radiation sources andhigh-precision linear measuring instruments, cylindrical surface in higher precision isrequired extensively. However, the accuracy of cylindrical surface has been always limitedby optical manufacture and testing technology. The current manufacture technology ofcylindrical surface has developed rapidly, while the high-precision optical testingtechnology still develops slowly, which cannot satisfy the application requirement ofcylindrical surface. So it is particularly important to study new technologies and methodsfor optical testing of cylindrical surface.Aiming at the problem on high-precision cylindrical measurement, this thesisproposes a new method for testing cylindrical surfaces with convergent beam andComputer Generated-Hologram (CGH). The main research is as follows:1. Some general methods for testing cylindrical surface including their demerits areintroduced. The basic principles of CGH and its manufacture methods are analyzed. Thedevelopment of testing cylindrical surface with CGH is summarized.2. A new cylindrical testing with convergent beam and CGH is proposed. The overalldesign principle of system and the relationship between the convergent beam and the scorespacing of CGH are analyzed. For an actual cylindrical surface, a testing system isdesigned and optimized with Zemax, and then the high-precision phase function of theCGH is obtained. In order to align the CGH accurately, the interferogram produced byregulator around the testing part of CGH with different position errors is given.3. The method to obtain the designing samples of the CGH according to its phase function is analyzed. A high-accuracy CGH is fabricated successfully with the laser directwriting technology.4. System errors are analyzed in detail using the error theory, including themanufacture errors and adjustment errors of all elements in the testing system.5. An actual cylinder is successfully tested with Zygo interferometer and themanufactured CGH. The measurement results demonstrate that using convergent beam andCGH, we can realize high-precision measurement of cylindrical surface rapidly andsimply.