Thiophene Dendrimers as Entangled Photon Sensor Materials

Abstract

The ability to do spectroscopy with a small number of entangled photons is an important development in the area of materials and sensing. This report investigates the effects of increasing thiophene dendrimer generation on the cross-section for both entangled (sigmaE) and random (deltaE) two-photon absorption cross-sections. Nonlinear optical properties of dendrimers are an interesting area of study because of potential applications in optical signal processing and remote sensing, and the use of a nonlinear optical material as a sensor for entangled photons offers great possibilities for applications in quantum lithography. Entangled two-photon absorption (ETPA) experiments and two-photon excited fluorescence (TPEF) experiments vary by at least 10 orders of magnitude in the photon flux used to probe the material. ETPA cross-sections from liquid samples as well as those of thin-film samples are investigated. An increase in sigmaE and de;taR with increasing dendrimer generation is observed, suggesting that the thiophene groups within the dendrimer nonlinearly absorb in a cooperative manner, which is further evidenced in the variation of cross-section per thiophene group. The nonlinear spectroscopic features obtained by the TPEF measurements were also obtained by the ETPA experiments, despite the fact that 10 orders of magnitude fewer photons are used in the latter technique. All dendrimer generations investigated in this work are found to have great potential for applications in quantum optical devices.

Nonlinear optical signals and spectroscopy with quantum light

“…In section III.C.1, we will further show that for off-resonant intermediate state(s) e -as is the case in most experimental studies to date (Dayan et al, 2004Guzman et al, 2010;Harpham et al, 2009;Lee and Goodson, 2006;Upton et al, 2013) -the two signals carry the same information.…”

Mechanisms of Light Energy Harvesting in Dendrimers and Hyperbranched Polymers

“…Although much of the context for this analysis has concerned dendrimeric systems acting as solar energy harvesters, there are several other important and emerging areas of application deserving mention, including molecular sensing [104][105][106], catalysis [104,107], medical photonics [104,108] and light-emitting diodes [109][110][111]. Most uses exploit the following generic properties: the possession of a multiplicity of chromophores that are responsible for initial photon absorption, and which can also act as relays; these groups display broad and intense absorption bands, and correspondingly strong emission bands; RET mechanisms are in place for the efficient transmission of electronic excitation by a sequence of transfers, providing a means for the direct routing of each excitation from peripheral to core chromophores; irreversibility of energy capture is achieved through intramolecular relaxation (energy losses) at each intervening site.…”

Internal organization of macromonomers and dendronized polymers based on thiophene dendrons

“…These Th dendrimers were used as entangled photon sensors. 46 Mitchell et al 47 prepared phenyl-cored Th dendrimers for organic photovoltaic devices, their power-conversion efficiency being recently overtaken by hexaperi-hexabenzocornene-cored Th dendrimers described by Wong et al. 48 and the hybrid gold-nanoparticle-cored dendrimers of Deng et al 49.…”