Ultrafast all-optical switching using doped chromoprotein films

TL;DR

This paper demonstrates femtosecond all-optical switching using doped chromoprotein films, showing potential for ultrafast data processing in next-generation communication networks.

Contribution

It provides the first experimental evidence of sub-200 fs all-optical switching using hydrated chromoprotein films, comparing different proteins and discussing practical applications.

Findings

Femtosecond transient grating experiments achieved <200 fs switching.

Hydrated yellow protein films enable ultrafast optical modulation.

Comparison with bacteriorhodopsin highlights material-specific performance.

Abstract

Next-generation communication networks require > Tbit/s single-channel data transfer and processing with sub-picosecond switches and routers at network nodes. Materials enabling ultrafast all-optical switching have high potential to solve the speed limitations of current optoelectronic circuits. Chromoproteins have been shown to exhibit a fast light-controlled refractive index change much larger than that induced by the optical Kerr effect due to a purely electronic nonlinearity, alleviating the driving energy requirements for optical switching. Here, we report femtosecond transient grating experiments demonstrating the feasibility of < 200-fs all-optical switching by hydrated thin films of photoactive yellow protein, for the first time, and compare the results with those obtained using bacteriorhodopsin. Possibilities for the practical utilization of the scheme in extremely high-speed optical modulation and switching/routing with nominally infinite extinction contrast are discussed.