Lunar Surface hologram

[Dinesh]

Has anyone seen this new NASA project about making holograms of the lunar surface? Apparently they're sending out a craft that looks a bit like a tank. The idea is that the craft lays down a polymer near the surface of the moon and a laser on the top of the craft zaps the plate, so you get a Single Beam Denisyuk. Then the plate is sent beneath the craft, like a tread on a tank, where UV sources develop the polymer, and the next plate is laid down. They intend to start on the dark side of the moon first. Apparently it's solar powered so they can take as long as it needs. I understand they're looking for polymers for this project. Interested parties should look for project 0401F001.

[BobH]

Isn't the phrase "single beam Denisyuk" redundant? Just sayin'.

[Joe Farina]

Isn't the phrase "single beam Denisyuk" redundant?

I wouldn't say so. There can be assisted Denisyuks, and I would prefer to call these assisted Denisyuks (or assisted single-beam reflection). I would reserve the term "split-beam" for cases where full control is had with both reference and object beam, with a beamsplitter. In the other cases (assisted Denisyuk) some extra object illumination would be thrown in by a "cheap and dirty" method. My opinion.

[Jeffrey Weil]

Hello Joe,

There are full, split beam, dennies. I've even seen them with multiple object lighting, so there's a few beam splitters involved. You don't have to make an H-1 for a reflection, only to image plane it (there are exceptions though, such as a focused image one step though).

Jeff W

[Joe Farina]

Hello Jeff,

Yes, I do like the term split-beam Denisyuk, when it applies. Actually, it's my favorite type of hologram.

[BobH]

But Denisyuk's recording geometry had only one beam that served as reference and object lighting with no other optical elements included. Adding mirrors or beamsplitters to get more object lighting beams makes it a plain ol' reflection hologram, not a "Denisyuk hologram". Another example: if one makes a transmission hologram transfer from a fully illuminated master plate, would it be proper to call it a "full aperture Rainbow (or Benton) hologram"? I wouldn't. Just nit pickin'.

[Joe Farina]

I think this is an interesting topic/thread.

I don't have a clear picture of the historical sequence of events regarding reflection holograms. As Bob mentioned, the first was a "pure" Denisyuk, and hence the term Denisyuk Hologram. (One beam and no more.) But after that, things start to get fuzzy. There were obviously many groups working on "assisted" Denisyuk and also fully split-beam reflection holograms at this time. When we think of "split beam" we almost automatically think of Leith & Upatnieks, but these were of course transmission holograms, not reflection. Two question I don't know are: 1) what are the first indications of assisted Denisyuk (no beamsplitter, but a mirror, lens, etc. for extra object illumination) and 2) what was the first time a fully split beam (with beamsplitter) reflection hologram was described?

Above, Jeff mentioned the term "split beam Denisyuk." However, that is the first time I've heard this terminology. Instead, I've always heard "split beam reflection."

The trouble is, whoever did the first split beam reflection was overshadowed the L. & U. work on transmissions, which later became the basis for image-planed holograms, and these became kind of the standard hologram. Split-beam master reflections kind of got lost in the shuffle.

I give Denisyuk a lot of credit, hence I like to use his name generally, to include "pure" Denisyuk holograms, as well as "assisted" Denisyuk for non-beamsplitter reflection holograms with extra object light. It's a combination of various things I've read over the years, combined with my own experience with such holograms. Fully split-beam reflection masters may be another matter, however. But I really don't know who did what, or when. Was split-beam reflection holography inspired more by L & U or by Denisyuk? Or both equally? Or, were other factors/influences involved? The terms Denisyuk, Assisted Denisyuk, and Split Beam Reflection are the common terms I've seen.

[Dinesh]

Denisyuk's first paper on the so-called (eponymous? ) Denisyuk hologram was in 1962 in "Soviet Physics - Doklady" Vol 7 (I think):
"Photographic Reconstruction of the Optical Properties of an Object in it's Own Scattered field"
In the paper, he states:

"The incident radiation on the object in this case had a wavelength of 5460 A. The standing wave pattern was recorded by means of Lippman photosensitive plates. For the objects we used spherical mirrors of various radii of curvature..."

So, the first "Denisyuk" was apparently a HOE of spherical mirrors. Whether this constitutes an absolute definition of a "Denisyuk" (single or otherwise) in the present sense may then be debatable, since this was not a hologram of an object, ie it was not a diffuse scattering source.

Then I found a paper on white light reconstruction of holographic images ( http://www.sciencedirect.com/science/ar ... 6366907438 ) published in 1966. I'd say that this is the first paper on display holography in reflection geometry, unless someone can come up with an earlier one. The first detailed study of the real Bragg planes that come from a reflection display hologram, ie non-uniform, two-dimensional Bragg planes, seems to be in a paper by Russell in 1981 ( http://www.sciencedirect.com/science/ar ... 7381901964 ). The Kogelnik paper, written in 1969 was analysis of idealised gratings that never occur in a real display hologram. The Russell paper does reference Denisyuk and also the first theory of two-dimensional Bragg structures by Solymar. I have the Solymar book, "Volume Holography and Volume Gratings" if anyone coming to PCGG wants to study it (What me, exploit my library as a recruiting tool? Never! ) Of course, it must have occurred to someone that the "Denisyuk" method based on the Lippman technique could also be used to record diffuse objects, but Yuri Denisyuk himself apparently never did this, or if he did, there's no published paper on it. At least none that I can find that shows objective proof, as opposed to "holo-stories".

So, is Denisyuk's paper in 1962 eponymous? In other words, is an "assisted Denisyuk", or a "split beam Denisyuk" an oxymoron? I'm not so sure. Whether a "pure" Denisyuk or an "assisted"/"split beam" Denisyuk, if the object itself is present and being recorded, as opposed to the recording of the diffractive/refracted waveform of an object (from an H1 or lens), then it seems to me that then you are making a "Photographic Reconstruction of the Optical Properties of an Object in it's Own Scattered field". A photographic reconstruction of an object from a diffracted or refracted field is not a reconstruction of an object in it's own field. However, I suppose that it is possible to generalise the meaning of "own field" to include an accurate representations of that field. I feel that's stretching the point, since the representation of the object's field as a diffracted field is then being used as a metaphor for the object's own field. The object creates it's own field by scattering radiation. The source of that radiation may be a simple "pass-through" light, as in the "pure" Denisyuk method, or the object may be illuminated in more complicated ways. But, the manner of the object's illumination is, it seems to me, irrelevant insofar as the illumination causes the object to scatter.

By the by, I don't know when the first Denisyuk style hologram was made. I took up holography in 1983 at Edwina Orr;s studio in London. This was a one-week course covering H1s, reflection H2's and rainbows. During that one-week course, Edwina kept praising American holographers, so after that course, in 1984, I came to America to meet American holographers. I landed in California (for various reasons) and decided to work my way East to New York (I had intended to use Greyhound, but they went on strike, forcing me to take a train from LA to New York, but that's another story). Anyway, in San Francisco, I met Gary Zellerbach running the Holo store on Haight Street. He informed me that mostly, West Coast holographers made reflection holograms, while East Coast holographers made transmission holograms. Then, in New York, I met Dan Schweitzer, who confirmed that. So, I expect the first reflection Denisyuks wre made in California. I'm sure that Bob can confirm or deny that. However, I was not aware of anyone "stealing light" to make an "assisted" Denisyuk (First time I'm hearing the term "assisted Denisyuk") While at ABNH, we used a technique for "stealing light", but making transmission holograms. When I came here to San Diego, we had a commission from Jason Sapan for a fairly difficult Denisyuk. The only way I could get it was by "stealing" the beam around the plate. Since this involves a fairly long coherence length, I think this must be a recent technique when long coherence length became freely available.

if one makes a transmission hologram transfer from a fully illuminated master plate, would it be proper to call it a "full aperture Rainbow (or Benton) hologram"?

At Icon, we called it an "achromat". However, Jeff has said that an "achromat" is a rainbow using the so-called Benton angles. We also called it an "open aperture achromat"

[Joe Farina]

Thanks for digging out those references, Dinesh, especially the first one regarding Stroke, because it ties in with the statement by Leith which I've attached. Two pages below (I'm not sure of the order of the images) are p. 202 and 203 of the Journal of Imaging Science and Technology, Vol. 41, No. 3, May/June 1997, and are from "Overview of the Development of Holography" by Leith. The interesting comments start under the section "Volume Holography." Leith says "the first report of this modification was given by A. Hoffmann et al." ("Inverted Reference-Beam Hologram" in Journal of the Optical Society of America Vol. 55, page 1559 (1965) by Hoffmann/Doidge/Mooney. No report was given concerning the date which Upatnieks tried to duplicate this work, and saw the "white light" image, other than "about the same time" as the report by Stroke and Laybeyrie, and also N. Hartman (patent filed 1966). Regarding Hartman, Leith said "his results were obtained several months earlier than those of the other contenders."

The other page attached below is from "Certain features of the development of display holography in the USSR" by Denisyuk, from SPIE 1600 (1991), page 376. I have a hard time following Densiyuk's writings, especially any indications of chronology, but he says "reflective 3-D holograms were carried out in our laboratory, too, however, due to the inertia of thinking, coins, medals, and other objects of a small depth were recorded on these holograms. The first large-scale reflective 3-D holograms with an image of a marble statuette has been obtained by Dr. G. A. Sobolev in 1967..." So the implication is that Denisyuk did the coins, etc. in 1967 or earlier. But it wasn't clearly stated, by any means.

[Dinesh]

True, no sense of time in Denisyuk's paper. He says that due to the "inertia of my thinking", he made coins etc. I wonder what "inertia" of his thinking means. I take it to read that since his concept was to record the scattered radiation caused by illumination, and any illumination on an object scatters off the two-dimensional front surface, it may not have occurred to him till 1967 that the back of an object also scatters light, and can be recorded. I don't know how available lasers were in Russia in the early 60's, but all we know is that the coins etc were shot between 1962 and 1967.

I especially liked the fact that he was bothered by reporters and "numerous beginners". These papers were quite mathematical. If you look at the foremost physics text book of the period, Feynman's "red books", there's only a cursory mention of diffraction from a mathematical point of view and certainly nothing at the level of these papers. Mathematics at this level would probably have been graduate level at least. So, where were these "beginners" from, I wonder? Another interesting point is that if the beginners were from the US, it shows that there was quite a bit of scientific co-operation between the US and the USSR during the heart of the cold war.

It seems a bit odd that Upatniks was amazed at the white light reconstruction, since he specifically states that Denisyuk's technique, and those of the later workers, of transferring the ref behind the plate was what made white light viewing possible. If he used a technique specifically designed to make white light viewing possible, why was he amazed when he found it to be white light viewable?