All-Optical Switching Demonstrated with Photoactive Yellow Protein Films

Integrated optics (IO) is a field of photonics which focuses on manufacturing circuits similar to those in integrated electronics, but that work on an optical basis to establish means of faster data transfer and processing. Currently, the biggest task in IO is finding or manufacturing materials with the proper nonlinear optical characteristics to implement as active components in IO circuits. Using biological materials in IO has recently been proposed, the first material to be investigated for this purpose being the protein bacteriorhodopsin; however, since then, other proteins have also been considered, such as the photoactive yellow protein (PYP). In our current work, we directly demonstrate the all-optical switching capabilities of PYP films combined with an IO Mach-Zehnder interferometer (MZI) for the first time. By exploiting photoreactions in the reaction cycle of PYP, we also show how a combination of exciting light beams can introduce an extra degree of freedom to control the operation of the device. Based on our results, we discuss how the special advantages of PYP can be utilized in future IO applications.

Automated summary

Integrated optics (IO) focuses on manufacturing circuits for faster data transfer and processing based on optical principles. The main challenge in IO is finding materials with proper nonlinear optical characteristics for active components in circuits and exploring the use of biological materials, such as the photoactive yellow protein (PYP). This study demonstrates the all-optical switching capabilities of PYP films in combination with an IO Mach-Zehnder interferometer (MZI) and explores the potential applications of PYP in future IO systems.