Ultrafast Photonic Logic Gates with Organic Chromophore Molecules

Ultrafast reverse saturable absorption has been analyzed in detail in chromophore-based borondipyrromethenes (BODIPYs) derivatives with femtosecond (fs) laser pulses at 800 nm and 850 nm. The effect of pulse intensity, pulse-width, thickness, concentration, nonlinear absorption coefficients and laser pulse shaping on transmittance has been studied and optimized for the all-optical switching in recently discovered BODIPY derivatives, 1,7-Diphenyl-3,5-bis(9,9-dimethyl-9H-fluoren-2-yl)-boron-diuoride-azadipyrromethene (ZL-61) and 1,7-Diphenyl-3,5-bis(4-(1,2,2-triphenylvinyl) phenyl)-boron-diuoride azadipyrromethene (ZL-22). The results have been used to design low-power and high-contrast all-optical fs NOT, universal NOR, and NAND logic gates. The ZL-61 at 800 nm and 850 nm results in enhanced contrast than ZL-22 and therefore, all-optical logic gates with ZL-61 have better percentage modulation. The excellent nonlinear optical properties of organic molecules and their derivatives have tremendous potential for ultrafast all-optical computing and ultrahigh bandwidth information processing.

I. Introduction

All-optical switching has attracted attention as it can potentially achieve the ultrafast and ultrahigh bandwidth information processing. Organic nonlinear optical (NLO) materials are necessary for achieving high-speed terahertz (THz) information processing when confronting practical challenges and meeting the combined requirements of ultrafast speed, ultrahigh bandwidth, ultralow energy, and ultra-compact devices [1]–[3]. Among various organic NLO compounds, borondipyrromethenes (BODIPYs) derivatives have emerged as an interesting chromophore materials, due to their remarkable properties, which includes strong UV absorption, sharp fluorescence peaks with high quantum yield, high molar extinction coefficients, easy functionalization, simple synthetic modification, highly conjugated structure, and photochemical and photothermal robustness [4], [5]. Various applications havebeen proposed, such as biological imaging, medical diagnostics and treatment, photodynamic therapy, high-performance organic solar cells, organic resistive memory, probes for food analysis and test strips [4], [6], [7]. Recently, two new derivatives of BODIPY namely, 1,7-Diphenyl-3,5-bis(9,9-dimethyl-9H-fluoren-2-yl)-boron-diuoride azadipyrromethene (ZL-61) and 1,7-Diphenyl-3,5-bis(4-(1, 2,2-triphenylvinyl) phenyl)-boron-diuoride azadipyrromethene (ZL-22) have been synthesized [8]. In this study, we theoretically investigated the ultrafast nonlinear absorption (NLA) of ZL-22 and ZL-61 at different intensities, pulse-width, wavelength, concentration and NLO coefficients. Furthermore, the reverse saturable absorption (RSA) characteristics have been optimized to achieve and design low-power, high contrast and ultrafast all-optical NOT, and universal NAND and NOR logic gates.