Nonlinear spectroscopy of deoxyribonucleic acid bases for DNA mesoscopic biophotonic devices

Abstract

In biological molecules such as DNA bases, the nonlinear effects take place from manipulating the properties of π-conjugated electrons. The molecular structure of DNA, with its considered optical nonlinearity, has generated interest in DNA photonics from both fundamental and applications perspectives. Looking for new design criteria to develop highly efficient photonic biomaterial-based devices, we performed the first simulations of nonlinear optical properties such as nonlinear refractive indices and two-photon absorption (2PA) coefficients of the four heterocyclic bases of 2′-deoxyribonucleic acid. The nonlinear refractive indices show an increase in the order cytosine > adenine > thymine > guanine. Moreover, the 2PA reveals an increase in the order cytosine > adenine > thymine = guanine. These values, along with that of the figure of merit, illustrate that both adenine and cytosine are promising biomaterials for ultrafast optical switching.