Accession Number:



Development of a Mechanically Mediated RF to Optical Transducer

Descriptive Note:

Technical Report

Corporate Author:


Personal Author(s):

Report Date:


Pagination or Media Count:



Detection and transmission of weak radio-frequency RF signals poses a significant challenge for modern electronic systems, in which lossy copper wires and thermal noise can corrupt sensitive information. Conversion, or transduction of these signals into the optical domain, however, enables enhanced detection sensitivity as well as long distance, low-loss transmission in optical fibers. Mechanically mediated transduction architectures, which rely upon the coupling of electronic and optical signals to a common mechanical oscillator, have sparked recent research interest for this application due to their ability to efficiently couple signals of drastically different frequencies. Recent advances in photonic integrated circuits PICs, which enable the manufacture of complex optical circuits, have demonstrated the potential to integrate mechanical resonators into optical designs, and therefore serve as an ideal platform for transducer development. Here, extending upon previous work on sensitive optomechanical interactions, we explore a novel, fully integrated technique for RF-to-optical transduction. In the proposed system, an RF signal displaces a coupled mechanical resonator placed within the evanescent field of an optical waveguide. This resulting displacement subsequently induces an optical phase shift due to the resonators proximity to the underlying optical waveguide. Placing this phase shifter within an interferometer enables sensitive optical phase detection, thus completing the conversion from an RF to an optical signal. To quantify the expected device performance, a theoretical model was developed and evaluated based upon the results of computational finite element simulations. A complete fabrication cycle was then conducted at the Naval Research Laboratorys Nanoscience Institute, which yielded devices for experimental verification of these conclusions and enabled a proof-of-concept implementation of the proposed architecture.

Subject Categories:

  • Electrooptical and Optoelectronic Devices

Distribution Statement: