Negative refraction in terbium at ultraviolet frequencies.

One of the key challenges in the development of negative index metamaterials is creating a sufficiently strong magnetic response in the material. Rare-earth ions can contain a strong optical magnetic response even in the ultraviolet region of the spectrum, which can be enhanced using magneto-electric cross-coupling. Using energies, transition strengths, and linewidths from atomic structure software, along with realistic inhomogeneous broadenings and densities in a solid, we simulate a negative index scheme using a terbium crystal at a wavelength of 282 nm.

Prospects for continuous-wave molecular modulation in Raman-active microresonators.

We propose the extension of existing molecular modulation techniques for continuous-wave optical modulation to Raman-active microresonators. Intense pump and Stokes modes inside a microresonator prepare a high coherence of the Raman transition between two ro-vibrational states. With the coherence prepared, any laser in the optical region can be coupled to the microresonator and be modulated.