Dynamic axial-position control of a laser-trapped particle by wave-front modification.

Journal article

The axial position of a laser-trapped particle has been controlled by modification of the wave front by means of a membrane deformable mirror. The mirror gives wave-front modulation in terms of Zernike polynomials. By modulation of the Zernike defocus term we can modulate the particle position under conditions of laser trapping. A polystyrene particle of 1-microm diameter was moved along the optical axis direction for a distance of 2370 nm in minimum steps of 55.4 nm. We also demonstrated particle oscillation along the optical axis by changing the focal position in a sinusoidal manner. From the frequency dependency of the amplitude of particle oscillation we determined the spring constant as 91.7 nN/m.

Authors: Ota, T; Kawata, S; Sugiura, T; Booth, M; Neil, M

• Publication status: Published
• Journal: Optics letters
• Volume: 28
• Issue: 6
• Pages: 465-467
• Publication date: 2003-03-01
• DOI: 10.1364/ol.28.000465
• EISSN: 1539-4794
• ISSN: 0146-9592
• Language: English