title: Laser spot position dependence in photothermal mode cooling of a microcantilever.
abstract: We explore the laser spot position (LSP) dependence of photothermal mode cooling in a microcantilever-based Fabry-Perot cavity. Experiments on photothermal cooling demonstrate that the direction of photothermal backaction on the first two cantilever modes is LSP dependent, which can be either parallel or antiparallel. A theoretical analysis of this LSP-dependent effect identifies the parallel and the antiparallel coupling regions along the lever. Simulation results are in quantitative agreement with our experimental observations. We conclude that the cooling limit imposed by photothermal mode coupling can be surmounted by operating in the parallel coupling region.
authors.affiliation: State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institution of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Fu
authors.forename: Cunding
authors.initials: C
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Jiaru
authors.initials: J
authors.lastname: Chu
authors.forename: Gengyu
authors.initials: G
authors.lastname: Cao