Optical vortex microscope is an optical system in which the beam illuminating the sample contains the optical vortex- a characteristic structure which contains a point of zero amplitude and undefined phase. Such a beam is very sensitive to the phase or amplitude defects which are introduced into it. In this paper we analyze experimentally the response of the optical vortex microscope to the small phase changes introduced into the beam.
One of the challenges for the Optical Vortex Scanning microscope is to find the effective procedures for surface
topography reconstruction. We proposed an experimental setup to support solution of this problem. The Spatial Light
Modulator (SLM) is used as a phase object. SLM allows to generate phase disturbance in the range 0-2π, which can be
easily introduced into the beam carrying optical vortex. Our system gives an opportunity to measure optical vortex
response due to phase modifications introduced by the SLM and investigate vortex sensitivity. We tested how the object
position, size affects vortex and position of the vortex point inside the beam.
In this work we consider a microscopic optical system in which the beam with an optical vortex illuminates the sample.
The sample modifies the geometry of the vortex beam wavefront and the information about it is transferred into the
detection plane. It is shown that the beam at the detection plane can be represented by two parts: non-disturbed vortex
part and sample part. We propose and test a scheme for recovering the phase changes caused by sample inserted into
the vortex beam. The numerical simulations are supported by the experimental work.
We consider a microscopic system in which the focused Gaussian beam with the embedded vortex illuminates the sample. The vortex beam is very sensitive to any imperfections introduced into it. Small defects introduced into the dark area of the vortex beam causes the change in its internal structure. We investigate theoretically and experimentally how the small rectangular groove introduced into the beam at the critical plane influence the phase structure of the beam. The analytical model of the setup is provided and following it the scheme for recovering the information about the sample is proposed.
We present the analytical model describing the Gaussian beam propagation through the off axis vortex lens and the set of axially positioned ideal lenses. The model is derived on the base of Fresnel diffraction integral. The model is extended to the case of vortex lens with any topological charge m. We have shown that the Gaussian beam propagation can be represented by function G which depends on four coefficients. When propagating from one lens to another the function holds its form but the coefficient changes.
The optical system working with focused Gaussian beam carrying a higher order optical vortex is considered. Additionally the optical vortex movement inside the beam is proposed allowing the precise scanning of the sample inserted into the beam. The analytical formula for the Fresnel diffraction integral with the shifted optical vortex has been calculated and compared with the numerical results. The experimental validation of this problem has been also presented.
We consider an optical system in which the optical vortex moves inside the focused Gaussian beam. The vortex movement is due to the vortex lens inserted in front of the focusing objective. We gradually shift the vortex lens along the x-axis which is perpendicular to the axis of laser beam propagation (z-axis). This causes that in the image plane vortex moves along a straight line but the line inclination depends on the position of the observation plane. There is a characteristic position of the observation plane, in which the vortex trajectory is perpendicular to the vortex plate shift. We call this plane a critical plane. The critical plane is sensitive to small phase variations which can be introduce by a transparent sample. We propose a way of retrieving the phase profile (at the critical plane) of such a beam. Our procedure is based on the Fourier transform phase demodulation method. We also investigate how the system reacts to the known phase variations introduced into the critical plane.
Magnetic fluids (ferrofluids) consist of magnetic nanoparticles (diameter ~10nm) which are dispersed in a liquid, often with the use of surfactants. They were first developed by NASA to address the unique requirements of moving liquid fuel in microgravity conditions. With a help of a holographic optical tweezers, interaction of magnetic nanoparticles with strongly focused laser beam was observed. When the light intensity was high enough, magnetic nanoparticles were removed from the beam center and they formed a dark ring. Creation process lasts less than 330μs and cannot be observed precisely even with ultrafast camera. Such rings exist when the laser beam is affecting the sample and disappear (with a lifespan of 10’th second range) after the laser is switched off. Moreover, when several rings are created simultaneously, complex interactions between them can be observed. In this work, the results of our experiments will be presented with hypotheses about the physical background of such a behavior.
In this paper we present the Optical Vortex Scanning Microscope (OVSM) in which the new scanning method induced by vortex lens movement is introduced. This method allows to scan the sample in a simple way. The behavior of the vortex position at the sample plane and phase retrieval algorithm is discussed. The new experimental results confirming the progress in the OVSM building are presented.
We study statistical properties of the recordings which contain time-dependent positions of a bead trapped in optical tweezers. Analysis of such a time series indicates that the commonly accepted model, i.e., the autoregressive process of first order, is not sufficient to fit the data. We show a presence of the first-order moving average part in the dynamical model of the system. We explain origin of this part as an influence of the high frequency CCD camera on the measurements. The proposed autoregressive moving average model appears to reflect perfectly all statistical features of the high-frequency recording data.
In this paper we report on the progress in building the superresolution microscope using optical vortices. The outline of the general idea is presented. Some of the specific problems are discussed in more details. Specifically, the scanning
method by vortex lens movement is discussed.
Scanning vortex microscope is a system in which sample is scanned by a Gaussian beam carrying optical vortex. We
report on a new method in which the sample is scanned by moving the optical vortex inside the focused beam spot.
Figure 1 shows a scheme of the optical system. The vortex lens shift induces a precise nanometre shift of the vortex point (i.e. point where the phase is undetermined) inside the focused spot. When moving the vortex lens along a straight line vortex point goes along a straight line of much smaller size and different orientation. There is a specific distance between the focusing lens and sample plane at which optical vortex is highly sensitive on sample topography. In this special plane vortex point’s movement is perpendicular to the vortex lens’ shift. Moreover, the angle of vortex point’s trajectory changes in a very rapid way. In the paper we investigate the dynamics of the vortex shift induced by different setup parameters.
In the previous paper the new scanning technique was proposed. The sample was illuminated by a focused laser beam
with an optical vortex. The vortex was introduced to the laser beam by vortex lens. When shifting the vortex lens the
optical vortex in the focused beam moves and scans the sample. In order to use this new scanning technique for
microscopic imaging a method for the focused vortex beam phase reconstruction is necessary. In this paper a fast and
accurate method for phase reconstruction of the focused vortex beam is investigated. It is shown that the propose method
is accurate enough to explore even small optical vortex shifts inside the focused beam.
In this paper the concept of optical vortex scanning microscope (OVSM) is presented. In the OVSM a sample is scanned
by the focused laser beam with optical vortex. The beam possessing an optical vortex contains a line along which the
phase is undetermined. At image plane this line is seen as the single point. The position of such special singular point
(vortex points) changes when the beam is diffracted by a sample. The vortex point sensitivity is higher than the
sensitivity of the whole focused beam. In the OVSM the position of vortex point is traced while scanning the sample. In
this paper the behavior of focused vortex beam, when scanning the phase step is studied. This simple example illustrates
both the OVSM idea and the method for data analysis.
The optical vortex is introduced into the incident Gaussian beam by a vortex lens. Then the beam with the
optical vortex is focused by a lens. By changing the position of the vortex lens we can shift the optical vortex
position inside the focused beam. We discussed the relation between vortex lens shift and optical vortex
movement inside the focused beam. The influence of optical system errors on this vortex movement is also
Optical singularities have focused much of attention for last thirty years. This paper is a short report on applications of
optical vortices both actual and potential. Unfortunately the optical vortices are still more promising features in optical
fields than working in real applications. However, there is a hope that they usefulness will grow in the future.
Optical vortex interferometer (OVI) is a useful tool to generate a regular lattice of optical vortices. The lattice is
generated by the interference of the three plane waves. As was shown in earlier papers such a vortex lattice can be
practically used in metrology. Application of optical vortex interferometer in metrology depends on the precision of the
vortex points localization. In this paper we present a novel localization method, which uses the phase shifting technique
applied to the additional fourth wave. Phase shift of the fourth wave doesn't change intensity in vortex points and
increases intensity gradient in their vicinity. The applicability of this method was verified in the experiment.
The optical vortex interferometer (OVI) generates regular lattice of optical vortices. As in standard two beam
interferometry the sample under measurements is introduced into one of the interferometer arm, which changes the
vortex lattice geometry and position. These changes can be measured and recomputed to the values of physical
quantities characterizing the sample. In this paper an overview of OVI configurations as well as basic properties is
given. The other solutions based on the three or more plane waves' interference field are also presented in brief.
The Optical Vortex Interferometer (OVI ) uses a regular lattice of optical vortex points. Such lattice can be generated by
amplitude division obtained in the modified Mach-Zender set-up. This was reported in our previous papers ( - ).
In this work the vortex lattice obtained by wavefront division is reported. We use the opaque screen with three or more
holes. The optical vortex lattice obtained using three holes in the screen reveals some special properties as it is in three
plane waves version of OVI. We analyze the properties of such lattice as well as lattice generated by four waves and
report on possible applications of this particular simple device. The theoretical considerations are illustrated by the
The optical vortex interferometer (OVI) is based on the regular net of optical vortices, which are generated by the
interference of three plane waves. In this paper the current state of the OVI is described. The paper starts with an outline
of the OVI theory. In the next step the three different versions of the optical body of OVI are shortly described. The
possible enhancements of the instrument are also discussed Next the methods for interfergoram analysis are presented
and the possible applications of the OVI are listed and shortly discussed.
The optical vortex interferometer (OVI) is based on the regular net of optical vortices, which is generated by the
interference of three plane waves. In this paper the use of OVI to phase determination is discussed. In classical
interferometry the phase of the wave is determined in respect to the phase of the reference wave. The quality of reference
wave must be checked by some other methods (like parallel glass plate test). It is shown that in case of OVI the phase of
the investigated wave can be reconstructed without referring to any other wave.
The regular net of optical vortices generated by the interference of three plane waves can be used for optical
measurements. The instrument based on such vortex net is called optical vortex interferometer. In this paper the special
properties of optical field generated by the interference of three plane waves are described. The technological issues of
the optical vortex interferometer are also discussed. Finally, two examples of application of the optical vortex
interferometer in context of the special properties of the interference field generated by three plane waves, are presented.
The optical vortex interferometer (OVI) is new optical instrument based on the regular net of optical vortices. Such net is generated by interference of three plane waves. In this paper the phase shifting method named internal scanning method, which enhances the OVI possibilities is discussed. The possible applications of this new method are also presented in brief.
Different methods of vortex localization in the vortices aided interferometry (VAI) presented in our previous work are presented and compared. The methods are tested first on the computer generated and then on the experimental interferograms. On the numerical generated interferograms vortex points can be localized with the accuracy of 1 pixel. On the experimental inteferograms different methods give the difference up to 4 pixels. Simple measuring scheme is applied to test this kind of the interferometer.
The presented paper may be treated as a short introduction to Singular Optics - the new branch of the contemporary optics and photonics. At the first part three main area of interest of the singular optics, Le. ray, phase and polarization singularities, are briefly presented. Second part gives better insight into the phase singularities, which are of special author's interest. Last part is devoted to the some possible phase singularities applications (interferometry and microscopy).
In this paper, it has been shown an apochromatic triplet can be designed without employing special glasses. This possibility is offered when optical system is composed of two lenses, i.e., hybrid and glass ones. Such a system is proposed and its spherochromatic aberration is determined. Aberration characteristic of the system is compared with that of conventional glass apochromat.
In this paper the diffraction of Gaussian beam with optical vortex by simple object is considered. The calculations are based on the scalar, near field diffraction integral. The dynamics of the optical vortex within the diffracted wave front is analyzed in particular.
In the paper the simple method of designing and manufacturing the synthetic holograms generating wavefront containing optical vortices is presented. The simple method of numerical analyses of plane wave passing through such holograms is also described.
Personal computers cause wide use of numerical methods for analysis of optical systems. The very important feature of algorithms applied for this purpose is their time efficiency. A fast algorithm for investigating the image quality of the hybrid lenses (i.e. glass lenses with hologram structure deposited on one of its surfaces) is presented in this paper.
In the paper the third order aberrations of holographic lenses recorded on quadrics of revolution are investigated. Analytical results presented in previous works are verified numerically using collimating and imaging holographic lenses as an example. The numerical calculations are performed in two ways: geometrical (ray tracing) and diffraction. We show the very small difference between aberration spots of holographic lenses recorded on sphere, ellipsoid, and hyperboloid with the same value of main curvature.
The imaging quality of holographic lenses depends on parameters that include the shape of a holographic lens surface or an input pupil position. Based on the formulas for third-order aberration coefficients derived for such cases, conditions that ensure the correction of aperture and field aberrations are given. The possibility of joint correction of spherical aberration, coma, and astigmatism is discussed. The formulas presented are illustrated with a number of examples; two types of holo-lenses are taken into account: imaging and focusing. For imaging quality assessment an aberration spot calculation method based on numerical evaluation of an appropriate diffraction integral is used. The results of this method are compared with the results of imaging quality estimation using the geometrical ray tracing method.
In our work we dealt with holographic lenses recorded on quadrics of revolution. According to third order aberration theory, we derived the expressions for the aberration coefficients in the case of holographic lenses with shifted pupil. We show that the aberration coefficients for such system could be expressed by the combination of aberration coefficients for the holographic lens with pupil in contact. We also show that ellipsoidal and hyperboloidal holographic lenses can be replaced by spherical lenses. We examine some possibilities of aberration correction by the substrate geometry and pupil position change.