Optical tweezers are of particular interest in various fields of science and technology such as atomic physics, nanotechnology and micromechanics. Today, there are many devices for manipulating microscopic objects using optical tweezers. In comparison with the most of known manipulation systems, the acousto-optic deflection is characterized by higher speed, the possibility to control several optical traps independently, high-precision movement of the trap within the field of view. In optical tweezers, longitudinal movement of micro-objects is also required. For this, special optical systems with variable characteristics, may be used. In this paper, we propose to combine these two approaches in one setup for 3D manipulation, i.e. to use acousto-optic scanning, using Bessel optical beams and an optical variosystem designed for longitudinal movement of the Gaussian beam waist at its constant diameter.
Spectrally tunable illumination is widely used for colorimetry, spectroscopy, spectral-domain optical coherence tomography and other applications. Most of the swept light sources suffer either from a limited number of spectral channels or from a spatial noise and speckles. In this paper, we discuss an approach based on acousto-optic filtration of wide-band illumination. We show experimentally that acousto-optical tunable filter (AOTF) provides a unique collection of features: arbitrary spectral tuning, multi-bandpass mode and acoustic frequency modulation. It allows assigning a number, positions and width of the spectral channels. Results of multiple experiments show that the proposed technique may become the basis of the swept light sources.