The evolution of The School's Stereogram Printer is traced, with individuals' contributions delineated. The optical performance of the machine is characterized through a series of tests, looking at the system's aberrations and resolution.
The development of the field of holography has depended on the coherence of laser light. The most meaningful attribute of coherence for holographers is the coherence length. Commonly, coherence length is regarded as the maximum optical path difference between two beams, such as those in a Michelson interferometer, that results in a discernable interference pattern. Herein we discuss two direct holographic methods of measuring coherence length, each yielding visually observable results. We begin by examining several theoretical models for laser spectral line-widths and the corresponding derivation of coherence lengths.
Scanning holography is a brand new concept in holographic optics. We describe various techniques of making scanning holograms and elaborate on the basic principles, relevant mathematics, applications and limitations of scanning holography.
The field of holography conipletely depends on the coherence of laser light. The most meaningful attribute of coherence for holographers is the coherent length. Commonly coherent length is regarded as the maxiinurct optical path difference between two bearas such as those in a Michelson interferorneter that results in a discernable interference pattern. Herein we discuss two direct holographic methods of measurements each yielding visually observable results. We begin by examining several theoretical models for laser spectral linewidths and their subsequent derivation of coherent lengths. 2. Spectroscopy and Line Shape Let us first discuss some basic tenants of laser spectroscopy since it leads us directly to the understanding of coherence. When the effects of the apparatus is progressively reduced and infinite resolving power is being used it is found that each spectral line consists of an intrinsic distribution of frequencies about the. line center. The profile of every spectral line has a finite width and characteristic shape which are determined by the conditions existing in the source and it is this profile which we now wish to consider. The line profile is important in determining many of the characteristics of gas lasers especially its coherence length. I. The Natural or Radiative Line Shape - the width of spectral lines errtitted by isolated stationary atoias. They are Lorentzian and honiogeneous. (i) Classical Model: Introducing the radiation reaction force it is easy to show
The philosophy of the holography department The School of the Art Institute of Chicago (SAIC) is discussed along with a fine arts curriculum designed to take into account the learning styles of art school students. A description of the facilities follow ending with a survey of artwork by the best students. Introduct ion Holography is almost unheard of in the art world when it is mentioned it is apt to be used as a metaphor for the ultimate in tastelessness. Occasionally a ''recognized'' artist will dabble in holography using the facilities of a commercial lab translating his concept into a hologram1. The results usually raise objections from the clique of handson holographic artists who feel that they are213 on the other hand are being discriminated against by the art world because they practice in a technical medium. As a way of improving the situation art school students must be better educated in the fine arts aspect of holography laboratory techniques and how to set up their own studios. For it will be only through the efforts of the " hands-on" workers will the medium fully realize its creative potential. This then is the major goal of this teacher: to help the students realize their full potential creating artful holograms with inexpensive equipment. Not only is it necessary that the holographic artist learn to work within the constraints of equipment at hand
It has been a long and elusive goal of display holographers to produce true multicolored images closely matched to that of the object. Much progress has been reported ecently by K. Bazargan1-'' T. Kubota2 P . M. Hubel and A. A. Ward '' and H. Owen and A. E . Hurst (6) However most of the works reported require sandwiches of different materials independently exposed. Herein we wish to report our recent work in " true color" holography using single lements of silver halide dichromated gelatin as propose by J. Blythe and the Du Pont photopolymer material. Also new sandwich combinations are reported. 2. HEURISTIC DEFINITION OF " TRUE" COLOR" Since laser light is required to record holograms the reconstructed image by an incandescent source will never recreate precisely the image of a multicolored object as it appears under natural lighting. At least two major factors contribute to this problem: the object may fluoresce and the reconstruction bandwidth will always be wider than laser lines causing color desaturation. Furthermore because color perception is subjective there cannot ever be complete agreement among different observers as to the " truthfulness" of the reconstructed image. We offer the following heuristic definition which is amenable to scientific verification: A hologram is said to have " true color" if it recreates an image which has the same combination of wavelengths and their relative intensities as those
It has been a long and elusive goal of display holographers to produce
true multicolored images closely matched to that o the objects. ,21uch
progress has been reported recently by K. Bazargan l , T. Kubo ", P. M. Hubel and A. A. Ward ' ' ' , and H. Owen and A. E. Hurst ".
However, most of the works reported require sandwiches of different
materials independently exposed.
Herein we report our recent work in "true color" holography using
single e],ents of silver halide, dichromated gelatin (as proposed by
J . Blyth ' ) ) , and the Du Pont photopolymer material . 1 new
sandwich combinations are reported.