High quality mechanical and optical properties of commercial silicon nitride membranes

B.M. Zwickl, W.E. Shanks, A.M. Jayich, C. Yang, A.C. Bleszynski Jayich, J.D. Thompson, J.G.E. Harris 2008. APL 92, 103125 (2008)

We have measured the optical and mechanical loss of commercial silicon nitride membranes. We find that 50 nm thick, 1 mm2 membranes have mechanical Q > 106 at 293 K, and Q > 107 at 300 mK, well above what has been observed in devices with comparable dimensions. The near-IR optical loss at 293 K is less than 2 x 10-4. This combination of properties make these membranes attractive candidates for studying quantum effects in optomechanical systems.