---
title: "History of metamaterials"
chunk: 3/5
source: "https://en.wikipedia.org/wiki/History_of_metamaterials"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:39:47.132262+00:00"
instance: "kb-cron"
---

Much of the historic research related to metamaterials is weighted from the view of antenna beam shaping within microwave engineering just after World War II. Furthermore, metamaterials appear to be historically linked to the body of research pertaining to artificial dielectrics throughout the late 1940s, the 1950s and the 1960s.  The most common use for artificial dielectrics throughout prior decades has been in the microwave regime for antenna beam shaping. The artificial dielectrics had been proposed as a low cost and lightweight "tool". Research on artificial dielectrics, other than metamaterials, is still ongoing for pertinent parts of the electromagnetic spectrum.
Pioneering works in microwave engineering on artificial dielectrics in microwave were produced by Winston E. Kock, Seymour Cohn, John Brown, and Walter Rotman. Periodic artificial structures were proposed by Kock, Rotman, and Sergei Schelkunoff. There is also an extensive reference list that is focused on the properties of artificial dielectrics in the 1991 book,   Field Theory of Guided Waves  by Robert E. Collin.
Schelkunoff achieved notice for contributions to antenna theory and electromagnetic wave propagation.
"Magnetic particles made of capacitively loaded loops were also suggested by Sergei Schelkunoff in 1952 (who was a senior colleague of Winston Kock at
Bell Labs at the time). However, Schelkunoff suggested these particles as a means of synthesizing high permeability (and not negative) values
but he recognized that such high permeability artificial dielectrics would be quite dispersive."
W.E. Kock proposed metallic and wire lenses for antennas. Some of these are the metallic delay lens, parallel-wire lens, and the wire mesh lens. In addition, he conducted analytical studies regarding the response of customized metallic particles to a quasistatic electromagnetic radiation. As with the current large group of researchers conveying the behavior of metamaterials, Kock noted behaviors and structure in artificial materials that are similar to metamaterials.
He employed particles, which would be of varying geometric shape; spheres, discs, ellipsoids and prolate or oblate spheroids, and would be either isolated or set in a repeating pattern as part of an array configuration. Furthermore, he was able to determine that such particles behave as a dielectric medium. He also noticed that the permittivity "ε" and permeability "μ" of these particles can be purposely tuned, but not independently.
With metamaterials, however, local values for both ε and μ are designed as part of the fabrication process, or analytically designed in theoretical studies. Because of this process, individual metamaterial inclusions can be independently tuned.
With artificial dielectrics Kock was able to see that any value for permittivity and permeability, arbitrarily large or small, can be achieved, and that this included the possibility of negative values for these parameters. The optical properties of the medium depended solely on the particles' geometrical shape and spacing, rather than on their own intrinsic behavior. His work also anticipated the split-ring resonator, a fabricated periodic structure that is a common workhorse for metamaterials.
Kock, however, did not investigate the simultaneous occurrence of negative values of ε and μ, which has become one of the first achievements defining modern metamaterials. This was because research in artificial materials was oriented toward other goals, such as creating  plasma media at RF or microwave frequencies related to the overarching needs of  NASA and the space program at that time.
Walter Rotman and R.F. Turner advanced microwave beam shaping systems with a lens that has three perfect focal points; two symmetrically located off-axis and one on-axis. They published the design equations for the improved straight-front-face lens, the evaluation of its phase control capabilities, scanning capabilities, and the demonstrated fabrication techniques applicable to this type of design.
Rotman invented other periodic structures that include many types of surface wave antennas: the trough waveguide, the channel waveguide, and the sandwich wire antenna.

== Photonic structures ==

"At frequencies of a few hundred gigahertz and lower, electrons are the principle particles which serve as the workhorse of devices. On the other hand,
at infrared through optical to ultraviolet wavelengths, the photon is the fundamental particle of choice."
The word 'photonics' appeared in the late 1960s to describe a research field whose goal was to use light to perform functions that traditionally fell within the typical domain of electronics, such as telecommunications, information processing, among other processes. The term photonics more specifically connotes:

The particle properties of light,
The potential of creating signal processing device technologies using photons,
The practical application of optics, and
An analogy to electronics.
Hence, as photonic materials are used, the photons, rather than electrons, become the fundamental carriers of information. Furthermore, the photon appears to be a more efficient carrier of information, and materials that can process photonic signals are both in use and in further development. Additionally, developing photonic materials will lead to further miniaturization of components.
In 1987 Eli Yablonovitch proposed controlling spontaneous emissions and constructing physical zones in periodic dielectrics that forbid certain wavelengths of electromagnetic radiation. These capabilities would be built into three-dimensional periodic dielectric structures (artificial dielectric). He noted that controlling spontaneous emission is desirable for semiconductor processes.

== Exceptional phenomena ==