Holographic optical elements with several optical functions recorded in a single layer have advantages in many applications. They have been difficult to fabricate because when they are recorded simultaneously in a single layer, spurious holograms are formed from the crosstalk between the recording beams. For some materials, sequential recording is a solution, but the mobile nature of photopolymer materials during recording prohibits the usual sequential techniques. The result has been that the crosstalk problem has required such holograms to be made from multiple layers causing both increased cost and reduced performance. This paper describes a method of recording such multiple elements in a single layer that completely eliminates such crosstalk holograms. The beams that form each hologram function included in the element are shuttered on in pairs for short intervals. Only the recording beams that form a desired hologram are present at any given time. No crosstalk occurs, since no unwanted beams are ever present. All holograms grow at the same rate as they each in turn receive short exposures. The round of exposures is repeated many times until they are all fully exposed. By keeping each round's exposures short, all holograms form essentially simultaneously, ensuring that they all see nearly the same recording material characteristics at the same stage of their development. This equalizes the recording of each element, even though the characteristics of the recording material change drastically and nonlinearly during the recording.
Consider the whole class of holographic optical elements which either contain pictorial image information or have the
ability to modify wavefronts. Even after many years of development, there are pitifully few marketable applications.
The visionary promises that holography would create a revolution in the optics and display industries have not been
fulfilled. Time has shown that, while it was relatively simple to dream up ideas for myriad applications, these ideas have
generally not moved beyond laboratory demonstrations. Exceptions are a few items such as optical elements for
supermarket scanners, head-up displays and laser diode lenses.
This paper addresses:
1. The many promises of holographic elements
2. The difficulties of practical implementation
3. A reassessment of research and development priorities
To give simple examples of these points, they are discussed mainly as they apply to one type of holographic
application: automotive displays. These familiar displays give a clear example of both the promises and difficulties that
holographic elements present in the world of high volume, low-costproduction.
Automotive displays could be considered as a trivial application alongside more interesting fundamental research
programs or high cost, sophisticated military applications. One might even consider "trivial" automotive displays to be a
disreputable subject for serious researchers. The case is made that exactly the opposite is true.
The resources for large scale development exist only in a healthy commercial market. An example is the Japanese
funding of high technology through commercial product development. This has been shown to be effective in the
development of other technologies, such as ceramics, semiconductors, solar cells and composite materials.
In like manner, if holography is to become an economically important technology, more and more competent
researchers must start looking outside the universities and military laboratories for support. They must involve themselves
in some of the "trivial" commercial applications.
Conference Committee Involvement (14)
Practical Holography XXVII: Materials and Applications
3 February 2013 | San Francisco, California, United States
Practical Holography XXVI: Materials and Applications
22 January 2012 | San Francisco, California, United States
Practical Holography XXV: Materials and Applications
23 January 2011 | San Francisco, California, United States
Practical Holography XXIV: Materials and Applications
25 January 2010 | San Francisco, California, United States
Practical Holography XXIII: Materials and Applications
25 January 2009 | San Jose, California, United States
Practical Holography XXII: Materials and Applications
20 January 2008 | San Jose, California, United States
Practical Holography XXI: Materials and Applications
21 January 2007 | San Jose, California, United States
Practical Holography XX: Materials and Applications
22 January 2006 | San Jose, California, United States
Practical Holography XIX: Materials and Applications
26 January 2005 | San Jose, California, United States
Practical Holography XVIII: Materials and Applications
19 January 2004 | San Jose, California, United States
Holographic Materials IX
21 January 2003 | Santa Clara, CA, United States
Holographic Materials VIII
21 January 2002 | San Jose, California, United States