Multichannel Digital Transmission in an Optical Network of Communicating Molecules

Abstract

In present telecommunication networks, information transfer relies on the interplay of optical and electrical signals. Data are communicated optically but processed electronically. Methods to maintain the propagating signals solely at the optical level must be developed to overcome the transmission capacities and speed limits imposed by the electronic components. We have demonstrated that molecular switches can be used to gate optical signals in response to optical signals. We have realized a simple optical network consisting of three light sources, one cell containing a solution of three fluorescent molecules, one cell containing a solution of a three-state molecular switch and a detector. The light emitted by the three fluorophores is absorbed by the three states of the molecular switch. Using this simple operating principle, we have shown that multichannel digital transmission can be implemented on an ensemble of communicating molecules relying exclusively on the interplay of optical inputs and optical outputs.

Molecular switches as photocontrollable “smart” receptors

“…The latter, called merocyanine, undergoes a cis-trans isomerization of the double bond in the pyran ring to produce a more stable product. [63][64][65][66][67][68][69][70][71] There is no disruption of the aromatic system and the absorption of the open form is dramatically redshifted to the visible region with respect to the closed spiropyran. The reversion to the closed form takes place either under thermal conditions or by a photochemical path.…”

Building pH Sensors into Paper-Based Small-Molecular Logic Systems for Very Simple Detection of Edges of Objects

“…7 We now use pH sensors to lift the field of molecular logic-based computation [8][9][10][11][12][13] to a much higher plane by demonstrating human-level computing by small molecules. Important advances in the level of complexity of molecular logic have been achieved by using chemical species to link gates, [14][15][16][17] by employing multi-component photochromics, 18,19 by using cuvet arrays, 20,21 and by the use of algorithmic pipeting protocols in multiwell plates. 22 We present the first instance of small synthetic molecules performing a major computation that humans do often during each waking hour.…”

Molecular 2:1 Digital Multiplexer

“…[4,5] A variety of other logic devices based on molecular phenomena have been reported. [6][7][8][9][10][11][12][13][14][15][16] Although some employ photochromes, in the vast majority at least one of the inputs requires physical addition of a chemical species that diffuses to a molecule and carries out a reaction, changing molecular structure.…”