The "Optical Assembler," aka the "Food Replicator"
Interview of Forrest Bishop
by Bill Spence
December 10, 1996
[[Note: This is a partial description of an idea I originally
had several years ago. It has not
proceeded past the conceptual stage, and is offered only for your entertainment.
Forrest Bishop ]]
F = Forrest Bishop
B = Bill Spence of NanoTechnology Magazine
B: Forrest Bishop on a different kind of replicator, one that does not
involve robot arms.
B: What does it use to manipulate?
F: This is very similar to what was on the original Star Trek episodes.
They called it the "Food Replicator". It was depicted as a box
in which things would simply appear when you wanted them, and so I use
that name because it has some of the same properties.
B: Is the food replicator...Earl Grey tea or ...general country doctor?
F: Yes, this is very speculative technology; itís not a for-sure thing;
itís more out on the fringe. The central idea is ...
B: Well, first, let me ask you, what is a replicator? It manipulates
atoms in foods and puts them in specific places where you want them to
F: Yes, to build an object, you want to create an object thatís
atomically precise. So, some kind of device to do this.
B: And one kind of system is basically robot arms that physically move
F: Yes, thatís the most popular version.
B: And this is completely different?
F: Yes, it uses electromagnetic energy in a structured electromagnetic
field to do the same thing.
B: To move individual atom, more than one atom:?
F: Individual atoms, molecules, small structures.
B: Small structures?
F: Yes, possibly.
B: What does this device look like? How does it function? How does it
F: The central idea is to create a structured electromagnetic field that
is variable in real time. The atoms are moved around by the electromagnetic
B: Atoms can be moved around by electromagnetic field?
B: What frequency are we talking about?
F: Roughly, light, visible spectrum, about [600 nanometers] depending
on the particular atom, depending on whether youíre trying to ionize it
B: So youíre pushing atoms with light?
F: Yes. This is already being done now. Itís partially based on ...
B: Trapping an atom with lasers, right?
F: Yes. This has already been accomplished. In this environment, imagine
a flat plate of emitters that are--each emitter is addressable; each emitter
is very tiny. By changing the timing--you have a row of them--by changing
the timing on them, you can create a wave front thatís steerable, just
as in a phased array radar.
B: OK. Light frequency.
F: Yes. So, a planar array of these --
B: A whole plane.
F: A whole plane consisting of a grid of emitters can construct a beam
of the frequency of your choice. The frequency can be varied over [time,
space, and phase] also, and that way, youíre creating a beam that is coherent
or different frequencies in different parts of it, thatís steerable over
the half-sphere. Ideally, you want to use emitters as small as possible--quantum
well lasers are one possibility.
B: Are they attainable?
F: They are.
B: In frequency?
F: Thereís already existing devices that are wholly suitable. These are
also called artificial atoms for the reason that you have -- in them,
you have an electron that is trapped in some kind of a potential well,
which then [radiates] as the voltage varies the size of that potential
B: Oh, itís [an] orbiting electron. Instant frequency of what itís
going to throw off in radiation?
F: Thatís right.
B: Pretty clever.
F: Yes. These are existing devices. Currently, researchers are trying
to make arrays of these which is going to be difficult, from the one emitter
________one its neighbor.
F: Because these are tiny [quantum] mechanical properties that youíre
B: So the radiation field of one would affect the other?
F: Yes, you could put it that way. The electric field of the voltage
thatís being used to adjust the potential well in one is affecting its
neighbor as well.
B: How would you overcome that?
F: In this idea, the way to overcome it, if you will, is simply through
computation [of] the wave function [of the entire planar array].
B: Would it take into consideration how one field affects the other?
And changing whatever parameters necessary?
F: Thatís right. It would take a massive amount of computer power.
B: OK, so you have a plate.
F: Yes, behind this plate, you have -- the equivalent of millions of
supercomputers are needed to run this.
B: Oh, that much power?
F: Thatís right. Youíre running in real time, and in this case, real
time means youíre obtaining a type of _________ range, so itís a huge
computational problem that require nanocomputers in order to realize it.
B: I see. So youíve got one plate with a hemisphere thatís completely
controllable where the wave is, and even what frequency it is. Then what?
F: Then what? Now, imagine two of these plates facing each other. A quantum
well emitter is also a receiver. A wave that comes in will cause a electron
or quantum well emitter to transition to a level, if it is the correct
frequency, which it will be, because it is part of the same system to
design that in. Therefore, you can create a standing between two plates.
You can steer that wave; you can, by phase shifting between the two plates,
you can cause the nodes, the standing of the nodes...
B: Where thereís energy and where thereís no energy.
F: Yes, it vibrates something down, kind of like a violin string, and
there are certain points on it that where the field strengths donít change,
called the nodes, and at those points is where you place an atom and have
it stay. Itís kind of similar to, if you take a board and want to saw
on it, sawdust will bounce up and down on the boards and collect in the
nodes, which is the places on that board that arenít moving up and down.
Some parts of the board move and some stand still, and thatís where the
sawdust collects. Itís a little bit like that.
B: So you could have atoms that would stay in the low-energy spots.
F: Yes, which is the nodes.
B: But you could move those nodes, is that correct?
F: Right, by phase shifting between the two plates, you could move the
nodes back and forth, and the atoms, theoretically, will move with the
B: Aha! So, you can move atoms in one axis.
F: Yes, one axis.
B: So far.
F: So far. Now, make it six plates. Now you can construct a three-dimensional,
fully specified, electromagnetic standing-wave field. You can move it,
and the atoms that are in it can be moved, shifted, in space.
B: Relative to each other?
F: Relative to each other, and relative to the box.
B: A lot closer together, if need be, or want?
F: Youíd want it to be.
B: Yes, I guess you would want it to be.
F: Yes, the idea is to inject an atom and have a wave front set up at
that point that catches that atom, or small molecule, or what have you,
perhaps you want to hit it with high energy to ionize it, to create a
radical group, and then you use the standing waves to move it, in three
dimensions, over to where you want it, and theoretically, cause a reaction.
B: Oh, in other words, bring it closer to another atom or molecule and
cause a reaction.
F: Yes, [close to the structure] youíre building. Cause a reaction.
B: And because you have so much resolution, you could inject lots of
atoms at one time in lots of places.
F: Because you have lots of computational power, you should be able to
do that. Every time you place an atom in this electromagnetic field, its
field interacts with that field and, in principle, you can deduce the
location of that atom by...
B: By its shadow?
F: By its effect on the overall field.
B: OK, so you constantly know where the position of all the atoms are,
in real time?
F: Yes, like I say, this is getting kind of far out there. Another problem
is the wavelength is, say, 500 nanometers, which is much greater than
the positional accuracy required for reactions. However, by time-averaging
the position of that atom, you should be able to deduce its position to
a small fraction of a wavelength, in other words, to the resolution required
for positional chemistry.
B: All right. So, what weíve got here is a box that you can inject atoms
into and grab them with standing, very complex lightwaves, and literally
move them around independently and get them into position to go into place.
As opposed to robot arms, youíre using lightwaves, energy. It sounds very
F: And the higher frequency lightwave can be used [to knock] an electron
off an atom to create a radical group, and at the desired time.
B: Oh, so, itís more reactive; can jump into...
F: Remember, I was saying the plane consists of tuneable quantum well
lasers that have a spatial frequency distribution so that you can address
that atom with the UV ray you want.
B: Sounds pretty utilitarian to me. Itís very useful.
F: Yes, itís a lot of speculation. It may or may not happen. Thereís
some research and ideas that are similar to this already being done, so...
B: Briefly, what is that research?
F: Well, I just learned of a fellow--I think heís simply conceived it--with
what he calls an "optical crystal"--I think thatís what he calls
it--and it is kind of the same idea, of having a three-dimensional standing
wave and placing atoms in the nodes, but not shifting it, but placing
atoms in the nodes such that they form a lattice structure thatís like
a crystal, except the atoms are actually separated quite a distance, at
least one wavelength of light apart, but theyíre in a lattice. Now, as
Iíve said before, the presence of those atoms alters the field, alters
the electromagnetic field in spots, and therefore, gives it a new optical
property that it didnít have before those atoms were there.
B: And itís detectable.
F: Yes. For instance, the index of refraction would be different than
if it was a box of [just] electromagnetic [energy]. And so by, for instance,
changing the frequency, youíre changing the lattice spacing, youíre altering
.. the [optical] properties of this volume ....
B: With this Optical Assembler...
F: Thatís a good name for it.
B: What do you feel like you could build? Anything? A cup of Earl Grey?
F: No, itís so speculative that Iím already out on a limb, and I donít
know how much further I want to go. Conceivably, anything; practically,
thereís a lot of unanswered questions. Somewhere between there.
Copyright ©1967-2004, Forrest Bishop, All Rights Reserved