A novel polymeric sheet with embedded micro optical resonant cavities for wall pressure measurements

摘要

In this paper, we present a novel untethered micro-photonic sensor for wall pressure measurements. The sensor concept is based on the frequency shift of the emission spectrum of a whispering gallery mode (WGM) micro-laser. Any change in the morphology of the laser cavity induces a shift in its emission spectrum. In other words, the laser cavity acts as a sensing element. The proposed prototype sensor consists of a thin polymeric slab with embedded micro-photonic spherical lasers with diameter less than 100 pun. The spherical micro-lasers are optically pumped via a remote laser or lamp. The emission spectrum from the micro-laser is recorded using a monochromator. Small changes in the external pressure acting on the polymeric sheet induce tiny changes in the morphology (WGM) of the laser cavity. Monitoring these WGM shifts for several micro-lasers in the sheet allows the distributed wall pressure on the sheet to be measured.