title: Wide cantilever stiffness range cavity optomechanical sensors for atomic force microscopy.
abstract: We report on progress in developing compact sensors for atomic force microscopy (AFM), in which the mechanical transducer is integrated with near-field optical readout on a single chip. The motion of a nanoscale, doubly clamped cantilever was transduced by an adjacent high quality factor silicon microdisk cavity. In particular, we show that displacement sensitivity on the order of 1 fm/(Hz)(1/2) can be achieved while the cantilever stiffness is varied over four orders of magnitude (≈0.01 N/m to ≈290 N/m). The ability to transduce both very soft and very stiff cantilevers extends the domain of applicability of this technique, potentially ranging from interrogation of microbiological samples (soft cantilevers) to imaging with high resolution (stiff cantilevers). Along with mechanical frequencies (> 250 kHz) that are much higher than those used in conventional AFM probes of similar stiffness, these results suggest that our cavity optomechanical sensors may have application in a wide variety of high-bandwidth AFM measurements.
authors.affiliation: Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Liu
authors.forename: Houxun
authors.initials: H
authors.lastname: Miao
authors.forename: Vladimir
authors.initials: V
authors.lastname: Aksyuk
authors.forename: Kartik
authors.initials: K
authors.lastname: Srinivasan