Giant optical rectification effect in nanocarbon films

Abstract

We present observations of the optical rectification effect in the nanocarbon film, which is excited by nanosecond pulses of a Nd:YAG laser in the absence of an external electric field. Effective second order susceptibility of the film material is found to be 10−6 CGSE, which is higher than that of conventional noncentrosymmetric crystals. The measured ratio of the dc voltage to the laser power is 500 and 650 mV/MW at the wavelengths of 1064 and 532 nm, respectively. This makes the nanocarbon materials a promising alternative to conventional semiconductor-based terahertz radiation sources.

Graphene-based quantum electronics

“…This effect, which was theoretically anticipated [100] and experimentally confirmed [101], can have important applications in THz electronics because optical rectification is a common and efficient method for generating and detecting THz signals [102]. The phenomenon of optical rectification relies on the generation or detection of the very small difference in frequency between two interacting waves that excite a certain material.…”

Optical rectification in self-assembled monolayers probed at surface plasmon resonance condition

“…Nevertheless, there are still few reports on the OR effects at a surface or in an ultrathin film. 9 In this paper we will report OR in a hemicyanineterminated alkanethiol self-assembled monolayer ͑SAM͒ on gold. Hemicyanine is a dye that shows a large second-order molecular polarizability originating from the strong intramolecular charge transfer from the dibuthylamino group to the pyridinium ion group.…”

Terahertz generation from graphite

“…At higher powers, the THz generation increases sub-linearly, indicating the onset of saturation. Graphite, in principle, is a material which possesses a centre of inversion symmetry, which prohibits χ (2) processes from the bulk of the crystal [8]. Based on the fact that graphite is more or less opaque to the pump beam, the generation of THz radiation near the surface must be localized to a thin layer consisting of multiple graphene planes within the penetration depth of the pump beam.…”

“…To this end, extensive studies have been performed on the transport properties and ultrafast carrier dynamics in graphite [6,7]. A recent report discusses the observation of second-order nonlinear optical rectification of nanosecond laser pulses by nano-graphite films, proposing that magnetic dipoles or electric quadrupoles are responsible [8]. This suggests the possibility of using graphite surfaces and related materials as sources of electromagnetic radiation in the THz region.…”