Generation of nondiffracting Bessel beam using digital micromirror device (original) (raw)

Experimental generation of Laguerre-Gaussian beam using digital micromirror device

Applied Optics, 2010

A digital micromirror device (DMD) modulates laser intensity through computer control of the device. We experimentally investigate the performance of the modulation property of a DMD and optimize the modulation procedure through image correction. Furthermore, Laguerre-Gaussian (LG) beams with different topological charges are generated by projecting a series of forklike gratings onto the DMD. We measure the field distribution with and without correction, the energy of LG beams with different topological charges, and the polarization property in sequence. Experimental results demonstrate that it is possible to generate LG beams with a DMD that allows the use of a high-intensity laser with proper correction to the input images, and that the polarization state of the LG beam differs from that of the input beam.

Generation of nondiffracting Bessel beams by use of a spatial light modulator

Optics Letters, 2003

A laser beam with phase singularities is an interesting object to study in optics and may have important applications in guiding atoms and molecules. We explore the characteristics of a singularity in a nondiffracting Bessel beam experimentally by use of a programmable spatial light modulator with 64-level phase holograms. The diffraction efficiency with 64-level phase holograms is greatly improved in comparison with that obtained with a binary grating. The experiments show that the size and def lection angle of the beam can be controlled in real time. The observations are in agreement with scalar diffraction theory.

Digital generation of shape-invariant Bessel-like beams

Optics Express, 2015

Bessel beams have been extensive studied to date but are always created over a finite region inside the laboratory. Means to overcome this consider multi-element refractive designs to create beams that have a longitudinal dependent cone angle, thereby allowing for a far greater quasi non-diffracting propagation region. Here we outline a generalized approach for the creation of shape-invariant Bessel-like beams with a single phaseonly element, and demonstrate it experimentally with a phase-only spatial light modulator. Our experimental results are in excellent agreement with theory, suggesting an easy-to-implement approach for long range, shapeinvariant Bessel-like beams.

Characterization of Bessel beams generated by polymeric microaxicons

Measurement Science and Technology, 2012

We present a quick, simple and accurate digital holographic characterization of the Bessel beams produced by polymeric microaxicons. This technique allows the numerical reconstruction of both intensity and phase of the beam at whichever point starting from a single acquired hologram. From these data, it is possible to go back to the axicon structure, and to gather information about their characteristics. In particular, the focal length and the depth of focus of the axicon lens are experimentally measured, and the full width at half maximum of the beam is obtained too. The depth of focus, very large for a Bessel beam with respect to a Gaussian one, is successfully exploited for optical trapping of micrometric objects.

Highly compact imaging using Bessel beams generated by ultraminiaturized multi-micro-axicon systems

Journal of the Optical Society of America A, 2012

Employing Bessel beams in imaging takes advantage of their self-reconstructing properties to achieve small focal points while maintaining a large depth of focus. Bessel beams are efficiently generated using axicons, and their utility in scanning imaging systems, such as optical coherence tomography (OCT), has been demonstrated. As these systems are miniaturized to allow, for example, endoscopic implementations, micro-axicons are required to assure the maintenance of a large depth of focus. We demonstrate here the design, fabrication, and application of molded micro-axicons for use in silicon-based micro-optical benches. It is shown that arrangements of multiple convex and concave axicons may be implemented to optimize the depth of focus in a miniaturized OCT system, using a telescopic optical arrangement of considerably shorter optical system length than that achievable with classical micro-optics.

Generation of multiple Bessel beams for a biophotonics workstation

Optics Express, 2008

We present a simple method using an axicon and spatial light modulator to create multiple parallel Bessel beams and precisely control their individual positions in three dimensions. This technique is tested as an alternative to classical holographic beam shaping commonly used now in optical tweezers. Various applications of precise control of multiple Bessel beams is demonstated within a single microscope giving rise to new methods for three-dimensional positional control of trapped particles or active sorting of micro-objects as well as "focus-free" photoporation of living cells. Overall this concept is termed a Biophotonics Workstation where users may readily trap, sort and porate material using Bessel light modes in a microscope.

Generating and measuring nondiffracting vector Bessel beams

Optics Letters, 2013

Nondiffracting vector Bessel beams are of considerable interest due to their nondiffracting nature and unique high-numerical-aperture focusing properties. Here we demonstrate their creation by a simple procedure requiring only a spatial light modulator and an azimuthally varying birefringent plate, known as a q-plate. We extend our control of both the geometric and dynamic phases to perform a polarization and modal decomposition on the vector field. We study both single-charged Bessel beams as well as superpositions and find good agreement with theory. Since we are able to encode nondiffracting modes with circular polarizations possessing different orbital angular momenta, we suggest these modes will be of interest in optical trapping, microscopy, and optical communication.

Shaping self-imaging bottle beams with modified quasi-Bessel beams

Coherent generated self-imaging bottle beams, typically formed by interfering two coherent quasi-Bessel beams, possess a periodic array of intensity maxima and minima along their axial direction. In practice, the overall quality of the self-repeating intensity patterns is prone to unresolved large intensity variations. In this Letter, we increased consistency of intensity of self-imaging bottle beams through a spatial frequency optimization routine. By doing so, we increased the effective length of self-imaging bottle beams by 74%. Further, we showed that this approach is applicable to higher-order self-imaging beams that display complex intensity structures. The enhancement in these modified self-imaging beams could play a significant role in optical trapping, imaging, and lithography.

Generation of dynamic Bessel beams and dynamic bottle beams using acousto-optic effect

Optics express, 2016

We present a novel optical configuration that allows for generation of ultra-high speed dynamic Bessel beams and dynamic bottle beams. The method is based on combination of the axisymmetric acousto-optic device and the spatial filtering enabled by a mask or a digital micromirror device. Selected features of dynamic non-diffracting beams and bottle beams are investigated using time-resolved approach with stroboscopic pulsed illumination, including spatial intensity distribution, spatial modulation factors, MHz-range temporal modulation, and scalability. The numerical simulations based on Fourier optics as well as experimental realizations are demonstrated.