Work

Sensitive broadband ultrasound sensor based on a low-loss high-Q fused-silica plano-concave microresonator

Year: 2025

Type: article

Abstract: Optical ultrasound sensors can achieve high sensitivity, small element size, and broadband frequency response. Polymer plano-concave microresonators (PCMRs) are among the most sensitive ultrasound sensors, but achieving further increases in sensitivity is limited by the optical absorption of the polymer cavity material. To address this, the use of fused silica as the cavity material is investigated. We present findings supporting the assertion that the low compressibility of fused silica compared to polymeric materials can be overcome by exploiting its extremely low optical absorption to achieve high Q-factors approaching 10 6 . We also show that the high Q-factors can introduce laser phase noise unless very narrow linewidth (<150 Hz) laser sources are employed. In this work, a fused silica PCMR ultrasound sensor is reported that has an NEP of 0.7 mPa/√Hz, a broadband frequency response with a −3 dB bandwidth of 2.5 MHz, and low directional sensitivity.

Source: Optics Express

DOI: 10.1364/oe.572433

Authors: David Martín-Sánchez, Edward Z. Zhang, Zhixin Liu, James A. Guggenheim, Paul C. Beard

Institutions: Consejo Superior de Investigaciones Científicas, Instituto de Microelectrónica de Sevilla, Universidad de Sevilla, University of Birmingham

Language: English

Topic: Mechanical and Optical Resonators

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270