Left-handed metamaterials (i.e. metamaterials with electrical permittivity and magnetic permeability both negative, giving rise to a negative index of refraction) have become a subject of increasing attention over the last few years; this is mainly due to their novel and unique properties (like backwards propagation, negative refraction, super-resolution, etc) which entail new capabilities in the manipulation of electromagnetic waves.
A large part of the current efforts in the left-handed metamaterials (LHMs) research is devoted to the achievement of LHMs operating in the infrared and optical part of the electromagnetic spectrum; such materials will give the opportunity to realize with light all the fascinating effects and capabilities that are possible with metamaterials. In this talk we review some of the main existing efforts to obtain left-handed metamaterials in the optical regime, and the main problems and constrains in the achievement of such materials. Moreover, we will present the main designs offered for a practical realization of optical LHMs and the main characteristics of the electromagnetic wave propagation in those designs. Based on those characteristics, we will provide optimization rules as to achieve left-handed structures with high operation frequency, large operation bandwidth and reduced losses.