Technological aspects on the fabrication of silicon-based optical accelerometer with ARROW structures

The fabrication and characterization of an optical accelerometer based on silicon technology and using BESOI wafers is presented. Instead of the standard total internal reflection (TIR) waveguides, AntiResonant Reflecting Optical Waveguides (ARROW) have been used. On the basis of a quad beam accelerometer design, a sensing waveguide has been placed on the seismic mass. Its misalignment with the waveguides located at the frame allows measuring the acceleration. The mechanical structure has been designed so as to have a span of 2 μm, that should provide with a sensitivity of 4.6 dB/g. Reference waveguides measured by end-fire coupling have low radiation and insertion losses (0.3 and 2.5 dB, respectively). High insertion losses are observed due to imperfections in polishing when V-grooves with glass anodic bonding are used. This fact causes the reduction of its sensibility to 2.3 dB/g.