A 3 pJ/bit free space optical interlink platform for self-powered tetherless sensing and opto-spintronic RF-to-optical transduction

Skyler Wheaton,Victor Lopez-Dominguez,Hooman Mohseni,Jialin Cai,Zhongming Zeng,Pedram Khalili Amiri,Hamid Almasi

doi:10.1038/s41598-021-87885-6

Skyler Wheaton, Victor Lopez-Dominguez + Show 5 more

Open Access

https://doi.org/10.1038/s41598-021-87885-6

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Abstract

Tetherless sensors have long been positioned to enable next generation applications in biomedical, environmental, and industrial sectors. The main challenge in enabling these advancements is the realization of a device that is compact, robust over time, and highly efficient. This paper presents a tetherless optical tag which utilizes optical energy harvesting to realize scalable self-powered devices. Unlike previous demonstrations of optically coupled sensor nodes, the device presented here amplifies signals and encodes data on the same optical beam that provides its power. This optical interrogation modality results in a highly efficient data link. These optical tags support data rates up to 10 Mb/s with an energy consumption of ~ 3 pJ/bit. As a proof-of-concept application, the optical tag is combined with a spintronic microwave detector based on a magnetic tunnel junction (MTJ). We used this hybrid opto-spintronic system to perform self-powered transduction of RF waves at 1 GHz to optical frequencies at ~ 200 THz, while carrying an audio signal across (see Supplementary Data for audio files).

Highlights

Tetherless sensors have long been positioned to enable generation applications in biomedical, environmental, and industrial sectors
The stepped quantum well modulators (SQWMs) is hybridized with a field effect transistor (FET) which acts as a high impedance input stage of the opto-tag
The current flow produced by absorbed photons from an input optical beam is harnessed by connecting the terminals of the SQWM across the drain and source of the FET

Summary

Introduction

Tetherless sensors have long been positioned to enable generation applications in biomedical, environmental, and industrial sectors. The transconductance of the FET produces an input gain which further increases the optical modulation that can be achieved with the SQWM for small applied gate voltages. The integration of a FET, SQWM, and spherical retro-reflector enables an opto-tag that has low angular sensitivity, low input referred noise, and on demand self-powered operation.

Results

Conclusion