Home › Content

Tensile strained InxGa1-xP membranes for cavity optomechanics

Tue, 2015-01-13 14:30 - Aspelmeyer Office
Printer-friendly versionSend by emailPDF version
Date: 
2014-05-23
Author(s): 

G. D. Cole, P.-L. Yu, C. Gärtner, K. Siquans, R. Moghadas Nia, J. Schmöle, J. Hoelscher-Obermaier, T. P. Purdy, W. Wieczorek, C. A. Regal, M. Aspelmeyer

Reference: 

Appl. Phys. Lett. 104, 201908 (2014)

URL: 

http://dx.doi.org/10.1063/1.4879755

We investigate the optomechanical properties of tensile-strained ternary InxGa1xP nanomembranes
grown on GaAs. This material system combines the benefits of highly strained membranes, similar to
those based on stoichiometric silicon nitride, with the unique properties of thin-film semiconductor
single crystals, as previously demonstrated with suspended GaAs. Here, we employ lattice mismatch
in epitaxial growth to impart an intrinsic tensile strain to a monocrystalline thin film (approximately
30 nm thick). These structures exhibit mechanical quality factors of 2  106 or beyond at room
temperature and 17 K for eigenfrequencies up to 1 MHz, yielding Q  f products of 2  1012Hz for a
tensile stress of 170 MPa. Incorporating such membranes in a high-finesse Fabry-Perot cavity, we
extract an upper limit to the total optical loss (including both absorption and scatter) of 40 ppm at
1064 nm and room temperature. Further reductions of the In content of this alloy will enable tensile
stress levels of 1 GPa, with the potential for a significant increase in the Q  f product, assuming no
deterioration in the mechanical loss at this composition and strain level. This materials system is a
promising candidate for the integration of strained semiconductor membrane structures with low-loss
semiconductor mirrors and for realizing stacks of membranes for enhanced optomechanical coupling.
VC