Microforce measurement method and apparatus
AssigneeNational Institute of Information and Communications Technology, Independent Administrative Institution
InventorsHiroaki Kojima, Kazuhiro Oiwa, Brenner Bernhard
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Abstract
A method and an apparatus for measuring the microforce acting between a micro particle fixed on the probe and the observation plane are described. The probe is feedback-controlled to be held motionless by canceling probe displacements caused by movements of the micro particle fixed on the probe, using irradiation pressure provided by a laser that applies photon pressure. The microforce acting between the micro particle fixed on the probe and the observation plane is measured by recording the time-varying laser output power. This allows probe fluctuations to be reduced to a few angstroms, and permits control of the distance to the target object to within a few nm, enabling measurement of microforces on the order of 0.1 pN.
Claims7
A microforce measurement method for measuring microforces acting between a micro particle fixed on a probe and an observation plane, comprising the steps of:
- keeping the probe position motionless by applying irradiation pressure to the probe with a photon pressure laser through feedback control of probe position changes caused by movement of the particle fixed on the probe;
- and
- measuring and recording the laser output power varying with time during said feedback control.
A microforce measurement apparatus for measuring microforces acting between a micro particle fixed on a probe and an observation plane, comprising:
- a photon pressure laser applying irradiation pressure to a probe;
- a feedback control means for keeping the probe position motionless by applying irradiation pressure to the probe with the photon pressure laser through feedback control of probe position changes caused by movement of the particle fixed on the probe;
- and
- a laser output power recording means for measuring and recording the laser output power varying with time during said feedback control.
Dependencies are inferred from the claim text.