Sensitive detection of acoustic emissions at frequencies in the range of kHz-MHz is vital for the health monitoring of mechanical structures. Fiber Bragg gratings (FBGs) are more attractive for such application compared to conventional piezoelectric transducers (PZTs) since they provide wideband response and are amenable to array sensing

Using Fabry-Perot filters based on fiber Bragg gratings (FP-FBGs), we improve upon the sensitivity in detection of the acoustic signals through better design of FP filters. We have also developed

• a low noise, high sensitivity optical receiver based on APD- TIA and band-pass filters,
• demonstrated improved signal to noise ratio (SNR) based on low power, 16-bit analog to digital converters (ADCs) and spectral estimation techniques.

Mr. Bipin Varghese was awarded the Prof. Achim Bopp prize for best M.Tech hardware project, based on this work.

Read more about it here.