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Analysis indicates that certain types of optically active media are capable of producing negative refraction and focusing of circularly polarized waves. It is established that a slab of such material acts just as Veselago's hypothetical left-handed media lens, providing subwavelength resolution as Sir Pendry's ideal lens, but for circularly polarized waves.

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We demonstrate that negative refraction occurs for both cw and pulsed electromagnetic waves when traversing from a "right-handed" (index > 0) to a "left-handed" (index < 0) material (LHM) which has causal dispersive intrinsic properties. We also demonstrate that a divergent line source spaced a distance H in front of a planar LHM slab and excited by either an impulse cw or a Gaussian frequency pulse is imaged at a distance H away, inside the LHM, and at H to the other side of the slab. The image size is approximately lambda consistent with limitations dictated by wave optics. We find no evidence of evanescent mode amplification. The studies were performed using numerical experiments with finite difference time domain solutions and incorporating a causal Lorentzian form for the frequency-dependent material properties.

Room temperature 57Fe Mössbauer spectra were taken on atomically ordered and disordered iron-cobalt samples as a function of composition between 25 and 75 at.% cobalt. The degree of long-range order was determined in selected samples using neutron diffraction. The maximum values of the effective field (He) and isomer shift (I.S.) occur at 25 at.% cobalt where He=−365.5±0.5 kOe and I.S. = +0.037±0.005 mm/sec (relative to pure iron). In the composition range studied increasing the number of cobalt neighbors to an iron atom either by ordering or by increasing the cobalt concentration decreases both I.S. and He. The maximum decrease with ordering of I.S., He, and the line widths occurs at 50 at.% cobalt, where the decrease is about 0.02 mm/sec for I.S. and 10 kOe for He. These results indicate that local atomic configurations play a significant role in the competition between positive and negative contributions to He. The data suggest a positive spin polarization contribution at the nucleus.