In this Letter, a test method based on oblique incidence is practically implemented in the interferometric measurement process. Three sets of wavefront data are achieved through cavity interference measurement with a ...In this Letter, a test method based on oblique incidence is practically implemented in the interferometric measurement process. Three sets of wavefront data are achieved through cavity interference measurement with a Fizeau interferometer and one oblique incidence measurement. An iterative algorithm is applied to retrieve the absolute surface shape of the test flat. By adding two sets of measurements, the absolute surface error of the interferometer＇s reference flat can be obtained. The new method can not only calibrate the reference flat error of interferometer, but also provide the absolute measurement method for high precision optical components applied in high power laser systems.展开更多
An improved reconstructing field method for measuring sound reflection coefficient of a large impedance surface at arbitrary incident angles is proposed in this paper. In order to get the reflection coefficient by the...An improved reconstructing field method for measuring sound reflection coefficient of a large impedance surface at arbitrary incident angles is proposed in this paper. In order to get the reflection coefficient by the Spatial Transformation of Sound Fields (STSF), the complex pressure on two parallel planes near by the material surface or the reflection surface must be measured. By the acoustic intensity measurement, the phases of complex pressure on two parallel planes are given. The results of the numerical simulations are shown that the error due to the finite size of the measurement area, and it may be reduced by using a dipole sound source.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11602280 and 61705246)
文摘In this Letter, a test method based on oblique incidence is practically implemented in the interferometric measurement process. Three sets of wavefront data are achieved through cavity interference measurement with a Fizeau interferometer and one oblique incidence measurement. An iterative algorithm is applied to retrieve the absolute surface shape of the test flat. By adding two sets of measurements, the absolute surface error of the interferometer＇s reference flat can be obtained. The new method can not only calibrate the reference flat error of interferometer, but also provide the absolute measurement method for high precision optical components applied in high power laser systems.
文摘An improved reconstructing field method for measuring sound reflection coefficient of a large impedance surface at arbitrary incident angles is proposed in this paper. In order to get the reflection coefficient by the Spatial Transformation of Sound Fields (STSF), the complex pressure on two parallel planes near by the material surface or the reflection surface must be measured. By the acoustic intensity measurement, the phases of complex pressure on two parallel planes are given. The results of the numerical simulations are shown that the error due to the finite size of the measurement area, and it may be reduced by using a dipole sound source.
