Design and fabrication of different types of holographic lenses, with analysis of their imagery and aberration

In this communication we have experimentally investigated and realized the following for the first time to the best of our information: two new types of hololenses; three compact two hololens imaging systems consisting of one each of the first and second type, one each of the second and first type, and two of the second type for coherent one to one imagery; and three compact four hololens imaging systems consisting of two of each of the first and second types, two of each of the second and first type, and four of the second type to form low f-number imaging systems. In addition, problems with the existing two hololens and four hololens imaging systems are discussed in the present study and a modified geometry is proposed with supporting mathematical analysis and experimental evidence. To reduce the problems of alignment difficulty, degrees of freedom and bulkiness associated with two hololens imaging systems, a third type of hololens is also reported, which can perform coherent one to one imagery by itself. All the imaging systems consisting of hololenses can perform imaging free from almost all monochromatic aberration for the conditions under which they were recorded. Complete analyses of recording, playback, imagery and aberration for all the hololenses and the compact two and four hololens imaging systems are performed. The resolution of all three types of hololenses is found to be 57 lines mm(-1), whereas the resolution of the compact two hololens imaging systems is 32 lines mm(-1). The average diameter of the focused spots of the first, second and third type of hololens are experimentally found to be 344.45 mu m, 339.75 mu m and 190.22 mu m respectively.