Investigation of interference field phase distribution with a lateral shearing interferometer

Problems of investigating the interference field are discussed. An investigation method is suggested which is based on using an imperfect plane-parallel plate lateral shearing interferometer for comparing aberrations in the arms of the two-beam interferometer which generates the interference field. It is demonstrated that equipartition of interference field fringes can be analyzed to an accuracy of λ/100 which exceeds the manufacturing accuracy of the lateral shearing interferometer.