Operating at telecom wavelengths (i.e., the range commonly used in fiber-optic
communications), the new device is completely scalable, from near-infrared to
terahertz wavelengths, and simple to manufacture.
Ho ho, very clever use of words there. Terahertz is far-far infrared, (1mm to .1mm (1,000,000-100,000nm) wavelength) while NIR is around 1,000nm. Visible light is 740-380nm.
To the best of my knowledge, (this isn't my field) nobody has ever made a visible-light metamaterial. The antennas are too small. There's no real physical reason we can't make red-light metamaterials, the problem is just fabrication. (A parallel can be drawn here between metamaterials, desktop nanofactories, and fusion reactors)
Additionally, it would be tricky to make a panchromatic metamaterial lens: metamaterials are tuned very precisely to one frequency, (color) constrained by the physical size of the antennas, and they can't transmit any others.
To the best of my knowledge, (this isn't my field) nobody has ever made a visible-light metamaterial. The antennas are too small. There's no real physical reason we can't make red-light metamaterials, the problem is just fabrication. (A parallel can be drawn here between metamaterials, desktop nanofactories, and fusion reactors)
Additionally, it would be tricky to make a panchromatic metamaterial lens: metamaterials are tuned very precisely to one frequency, (color) constrained by the physical size of the antennas, and they can't transmit any others.