title: Comment on "direct measurement of the oscillation frequency in an optical-tweezers trap by parametric excitation".
authors.affiliation: Department of Physics Simon Fraser University Burnaby, British Columbia, V5A 1S6, Canada. ydeng@sfu.ca
authors.forename: Yi
authors.initials: Y
authors.lastname: Deng
authors.forename: Nancy R
authors.initials: NR
authors.lastname: Forde
authors.forename: John
authors.initials: J
authors.lastname: Bechhoefer