Generation of reconfigurable optical traps for microparticles spatial manipulation through dynamic split lens inspired light structures

Abstract

We present an experimental method, based on the use of dynamic split-lens configurations, useful for the trapping and spatial control of microparticles through the photophoretic force. In particular, the concept of split-lens configurations is exploited to experimentally create customized and reconfigurable three-dimensional light structures, in which carbon coated glass microspheres, with sizes in a range of 63–75 μm, can be captured. The generation of light spatial structures is performed by properly addressing phase distributions corresponding to different split-lens configurations onto a spatial light modulator (SLM). The use of an SLM allows a dynamic variation of the light structures geometry just by modifying few control parameters of easy physical interpretation. We provide some examples in video format of particle trapping processes. What is more, we also perform further spatial manipulation, by controlling the spatial position of the particles in the axial direction, demonstrating the generation of reconfigurable three-dimensional photophoretic traps for microscopic manipulation of absorbing particles.

Tomographic Diffractive Microscopy: A Review of Methods and Recent Developments

“…In TDM under transmission configuration, fixing the setup, the sample along the x-axis was successfully rotated to give a quasi-isotropic resolution [61]. Using optical tweezers is another promising method [62][63][64][65][66]. To achieve complete configuration, a combination of specimen rotation and illumination rotation simultaneously is also feasible by adopting an integrated setup [67].…”

Microparticle Manipulation and Imaging through a Self-Calibrated Liquid Crystal on Silicon Display

“…We also present a method for microparticle spatial manipulation based on an LCoS display [12]. Before particle manipulation, they are firstly optically trapped into a three-dimensional light structure (optical bottle structure).…”

“…where Ĩ(µ,ν) is the Fourier transfer of Equation (12) and d is the axial distance from the image input plane to the particular position where we want to reconstruct the wavefront. So far, we have theoretically discussed the mathematical background to implement the IL holographic wavefront imaging through a double-sideband filter.…”

“…Into the amplitude modulation scheme, output intensity distribution can be customized by properly modifying the polarization spatial distribution of the wavefront, and projecting it over a linear analyzer, being this configuration commonly used for imaging proposes. Conversely, LCoS displays operating in the phase-only regime are commonly used for phase modulation, being of interest in a wide number of applications, such as microstructure fabrication [6], holography [7,8], biomedical applications [9], waveguide optics [10], optical switching [11], microparticle manipulation [12,13], etc. To guarantee an optimal working performance in all those applications, LCoS must be previously calibrated and optimized.…”

“…Once the LCoS display is optimized, we use it for optical applications. Two different applications we recently developed for microparticles imaging [23,24] and manipulation [12,13] are revised in this manuscript. First, we use such elements to realize customized three-dimensional light structures.…”