Spectroscopic implications of new holographic imaging methods

Abstract

Significant increases in luminosity, detection and resolution capabilities may result from extending to spectroscopic and astronomical instruments some of the new advances, recently made in the field of wavefront-reconstruction imaging (holography), first described by D. Gabor in 1948 1) 2) 3) 4). The recent advances 4−11) of which we have briefly described some early aspects elsewhere have already permitted us to obtain spectra in a holographic Fourier- transforming 7) 8) arrangement, using no scanning in the interferometer, and displaying the spectra by optical Fourier-transform reconstruction from the interferometric hologram 9), rather than by digital computation. In another work, we have now been able to holographically compensate a posteriori for the “slit spreading-effect”, in a coherent-light imaging system, and to retrieve the resolution by a corrtion-reconstruction method 10) 11). “Erasing” of selected image portions, by actually adding the complex amplitudes in two images, 180° out of phase, in a holographic arrangement has also been achieved 12) and may be used for increasing detection of selected image portions in astronomical and spectroscopic plates. Previously unpublished advances and some details of the new holographic imaging methods are given.