Two-photon 3D printing optical Fabry-Perot microcavity for non-contact pressure detection

Abstract

peer reviewedIn this work, a polymer Fabry-Perot interferometer-based microcavity via two-photon direct laser writing is proposed, designed, and experimentally demonstrated as an optical pressure sensor. The sensor comprises a film-based hollow cavity with a diameter of 350 μm and an annular flow channel with four drain holes, which is further sealed for pressure sensing. As the applied pressure varies, the cavity length changes accordingly. Here, a non-contact optical spectral demodulation system integrated with an optical microscopy was designed. An illuminated light was used for localizing the device and a broadband near-infrared light was coupled into an objective lens and the transmitted light was reflected by the device and detected by a spectral demodulation system. To demodulate the spectral signal, a Fourier demodulation algorithm was used to track the wavelength. The results showed that the sensor exhibited a high sensitivity of 398 pm/kPa and good stability. This work can be used for non-contact pressure detection in the critical field of biomedical and aerospace applications