Complete polarization and phase control for focus-shaping in high-NA microscopy

Kenny, Fiona; Lara, David; Rodríguez-Herrera, Oscar G.; Dainty, Chris

doi:10.1364/oe.20.014015

Cited by 89 publications

(40 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, the experimental setups providing such flexibility are more complex than ours. They involve employment of two modulators [49], a single modulator in a double-pass scheme [48,50] or one in a split-screen configuration [47], at the expense of increasing costs or reducing spatial resolution. In addition, since very precise pixel-to-pixel alignment is required and stability is plausibly worsened, they are not necessarily suitable for the kind of applications that we have discussed.…”

Section: Discussionmentioning

confidence: 99%

Holographic optical tweezers combined with back-focal-plane displacement detection

Marsà¹,

Farré²,

Martı́n-Badosa³

et al. 2013

Opt. Express

View full text Add to dashboard Cite

A major problem with holographic optical tweezers (HOTs) is their incompatibility with laser-based position detection methods, such as back-focal-plane interferometry (BFPI). The alternatives generally used with HOTs, like high-speed video tracking, do not offer the same spatial and temporal bandwidths. This has limited the use of this technique in precise quantitative experiments. In this paper, we present an optical trap design that combines digital holography and back-focal-plane displacement detection. We show that, with a particularly simple setup, it is possible to generate a set of multiple holographic traps and an additional static non-holographic trap with orthogonal polarizations and that they can be, therefore, easily separated for measuring positions and forces with the high positional and temporal resolutions of laser-based detection. We prove that measurements from both polarizations contain less than 1% crosstalk and that traps in our setup are harmonic within the typical range. We further tested the instrument in a DNA stretching experiment and we discuss an interesting property of this configuration: the small drift of the differential signal between traps.

show abstract

Section: Discussionmentioning

confidence: 99%

Holographic optical tweezers combined with back-focal-plane displacement detection

Marsà¹,

Farré²,

Martı́n-Badosa³

et al. 2013

Opt. Express

View full text Add to dashboard Cite

show abstract

“…While early studies mainly dealt with spatially homogeneous polarization states, in recent years interest in arbitrary spatially-variant polarized beams (ASPBs) has increased significantly due to their special properties compared to homogeneously polarized beams, which can thereby enhance the functionality of optical systems. Nevertheless, the generation of ASPBs can be a difficult task; while static techniques do not allow dynamic encoding of ASPB patterns [2][3][4][5], a solution can be found using spatial light modulators (SLMs) which can be considered as reconfigurable phase retarder devices controlled by computer [6][7][8][9][10][11][12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Reconfigurable beams with arbitrary polarization and shape distributions at a given plane

Maluenda¹,

Juvells²,

Martı́nez-Herrero³

et al. 2013

Opt. Express

View full text Add to dashboard Cite

Methods for generating beams with arbitrary polarization based on the use of liquid crystal displays have recently attracted interest from a wide range of sources. In this paper we present a technique for generating beams with arbitrary polarization and shape distributions at a given plane using a Mach-Zehnder setup. The transverse components of the incident beam are processed independently by means of spatial light modulators placed in each path of the interferometer. The modulators display computer generated holograms designed to dynamically encode any amplitude value and polarization state for each point of the wavefront in a given plane. The steps required to design such beams are described in detail. Several beams performing different polarization and intensity landscapes have been experimentally implemented. The results obtained demonstrate the capability of the proposed technique to tailor the amplitude and polarization of the beam simultaneously.

show abstract

“…In general, these techniques require three-dimensional (3D) focused electromagnetic fields, with special characteristics: shape, polarization coherence, and so on. Obtaining these specific features involves the suitable design of the input field [1][2][3][4][5][6]. Research on the polarization properties of highly focused fields has been mainly devoted on fully polarized light, whereas partially polarized waves have received less attention [7][8][9].…”

mentioning

confidence: 99%

Design of highly focused fields that remain unpolarized on axis

2014

View full text Add to dashboard Cite

Research on the properties of highly focused fields mainly involved fully polarized light, whereas partially polarized waves received less attention. The aim of this Letter is to provide an appropriate framework, for designing some features of the focused field, when dealing with incoming partially polarized beams. In particular, in this Letter, we describe how to get an unpolarized field on the axis of a high numerical aperture objective lens. The study of field distribution, in the focal region of a high numerical aperture (NA) focusing system, is attracting increasing attention because of their possible applications in many fields, e.g., electron acceleration, nonlinear optics, or particle trapping and manipulation. In general, these techniques require three-dimensional (3D) focused electromagnetic fields, with special characteristics: shape, polarization coherence, and so on. Obtaining these specific features involves the suitable design of the input field [1][2][3][4][5][6]. Research on the polarization properties of highly focused fields has been mainly devoted on fully polarized light, whereas partially polarized waves have received less attention [7][8][9]. Moreover, the use of partially coherent fields has been recently proposed as a suitable light source for optical trapping systems [10]; this kind of fields are also useful in tomography [11], plasmonics spectroscopy [12], or invisibility cloaking [13]. Accordingly, the aim of this Letter is to provide an appropriate framework for designing some features of the focused field, when dealing with incoming partially polarized beams. First, we relate the circular components of the transverse incident field with the circular and longitudinal content of the focused field; then, this formalism is extended to quasi-monochromatic statistically stationary incident beams. Finally, we focus on getting an unpolarized field on the axis of an imaging system with a high NA. Moreover, the polarization over the focal plane is also analyzed.The electric field distribution, at any point in the focal region of a high NA focusing system, is given by the well- where A is a constant, related to the focal length and the wavelength; k is the wave number, r and ϕ denote in this Letter the polar coordinates at the focal plane; and angles θ and θ 0 are represented in Fig. 1. Pθ denotes the so-called apodization function. obtained from energy conservation and geometric considerations; and E 0 is the so-called vector angular spectrum; this angular spectrum is usually written aswhere f 1 and f 2 are, respectively, the azimuthal and radial components of incident field (which we assume transversal). The unitary vectors e 1 and e 2 are given by e 1 ϕ − sin ϕ; cos ϕ; 0;e 2 θ; ϕ cos θ cos ϕ; cos θ sin ϕ; sin θ:Frequently, it is useful to write the angular spectrum using a convenient change of basis [15][16][17]. Instead of using the conventional radial and azimuthal description, it is advisable to describe the angular spectrum in terms of the circular content of the beam (see below). Accor...

show abstract

Complete polarization and phase control for focus-shaping in high-NA microscopy

Cited by 89 publications

References 28 publications

Holographic optical tweezers combined with back-focal-plane displacement detection

Holographic optical tweezers combined with back-focal-plane displacement detection

Reconfigurable beams with arbitrary polarization and shape distributions at a given plane

Design of highly focused fields that remain unpolarized on axis

Contact Info

Product

Resources

About