References

1

Ashkin A: Acceleration and trapping of particles by radiation pressure. Phys Rev Lett 1970. 24:156-159.

2

Ashkin A: Optical levitation by radiation pressure. Appl Phys Lett 1971. 19:283-285.

3

Ashkin A: Applications of laser radiation pressure. Science 1980. 210:1081-1088.

4

Ashkin A, Dziedzic JM, Bjorkholm JE, Chu S: Observation of a single-beam gradient force optical trap for dielectric particles. Opt Lett 1986. 11:288-290.
Original report of optical tweezers.

5

Ashkin A, Dziedzic JM, Yamane T: Optical trapping and manipulation of single cells using infrared laser beams. Nature 1987. 330:769-771.

6

Svoboda K, Block SM: Biological applications of optical forces. Ann Rev Biophys Biomol Struct 1994. 23:247-285.
Comprehensive review of optical tweezer techniques and theory with applications to biological systems.

7

Lyons ER, Sonek GJ: Confinement and bistability in a tapered hemispherically lensed optical fiber trap. Appl Phys Lett 1995. 66:1584-1586.
A single optical fiber drawn to a taper and fired to produce a hemispherical lens is shown to trap particles. A pair of fiber tweezers form a bistable trap which can be used to transfer particles controllably from one fiber to another.

8

Harada Y, Asakura T: Radiation forces on a dielectric sphere in the Rayleigh scattering regime. Opt Comm 1996. 124:529-541.

9

Ren KF, Gréhan G, Gouesbet G: Prediction of reverse radiation pressure by generalized Lorenz-Mie theory. Appl Opt 1996. 35:2702-2710.
Generalized Lorenz-Mie approach provides a unified framework for calculating radiation pressure due to realistically modeled focused Gaussian beams on spherical particles. Calculations cover the range from Rayleigh to Mie domains. Interresting predictions include the inability to axially trap 1 m diameter glass spheres in water with a focused Gaussian beam.

10

Wohland T, Rosin A, Stelzer EHK: Theoretical determination of the influence of the polarization on forces exerted by optical tweezers. Optik 1996. 102:181-190.
Hybrid wave optics / ray optics calculation of the axial and lateral forces on a latex sphere suspended in water trapped by a focused Gaussian beam. The axial displacement of the trapping point from the focal point is found to scale linearly with particle radius. Interesting predictions include the possibility of creating two axial trapping points for appropriately sized spheres.

11

Farsund Ø, Felderhof BU: Force, torque, and absorbed energy for a body of arbitrary shape and constitution in an electromagnetic radiation field. Physica A 1996. 227:108-130.
Calculation using Debye potentials of the forces exerted on an arbitrarily shaped particle with characteristic size ranging up to the wavelength of light. Describes how to address particles with nonlinear interactions with light.

12

Liebert RB, Prieve DC: Force exerted by a laser beam on a microscopic sphere in water: Designing for maximum axial force. Ind Eng Chem Res 1995. 34:3542-3550.

13

D'Helon C, Dearden EW, Rubinsztein-Dunlop H, Heckenberg NR: Measurement of the optical force and trapping range of a single-beam gradient optical trap for micron-sized latex spheres. J Mod Opt 1994. 41:595-601.

14

Rosin A, Wohland T, Stelzer EHK: Calculation and measurement of the axial forces exerted by photonic tweezers. Zoological Studies 1995. 34:167-169.

15

Friese MEJ, Rubinsztein-Dunlop H, Heckenberg NR, Dearden EW: Determination of the force constant of a single-beam gradient trap by measurement of backscattered light. Appl Opt 1996. 35:7112-7116.
Describes calibration of optical tweezer trapping potential using the power spectral density of fluctuations in light scattered by a trapped particle. The technique is applied to both Gaussian and optical vortex tweezers. Discusses potential applications to scanning force microscopy.

16

Simmons RM, Finer JT, Chu S, Spudich JA: Quantitative measurements of force and displacement using an optical trap. Biophys J 1996. 70:1813-1822.

17

Perkins TT, Smith DE, Larson RG, Chu S: Stretching of a single tethered polymer in a uniform flow. Science 1995. 268:83-87.
A strand of DNA affixed at one end to a colloidal sphere is stretched in an elongational fluid flow while the sphere is immobilized in an optical tweezer.

18

Smith DE, Wu XZ, Libchaber A, Moses E, Witten T: Viscous finger narrowing at the coil-stretch transition in a dilute polymer solution. Phys Rev A 1992. 45:R2165-R2168.

19

Bustamante C, Marko JF, Siggia ED, Smith S: Entropic elasticity of lambda-phage DNA. Science 1994. 265:1599-1600.

20

Marko JF, Siggia ED: Stretching DNA. Macromolecules 1995. 28:8759-8770. Marko JF, Siggia ED: Bending and twisting elasticity of DNA. Macromolecules 1996. 29:4820-4820.

21

Smith SB, Cui Y, Bustamante C: Overstretching B-DNA: The elastic response of individual double-stranded and single-stranded DNA molecules. Science 1996. 271:795-799.

22

Wang MD, Yin H, Landick R, Gelles J, Block SM: Stretching DNA with optical tweezers. Biophys J 1997: in press.

23

Wang D, Meier TI, Chan CL, Feng G, Lee DN, Landick R: Discontinuous movements of DNA and RNA in RNA polymerase accompanying formation of a paused transcription complex. Cell 1995 81:341-350.

24

Yin H, Wang MD, Svoboda K, Landick R, Block SM, Gelles J: Transcription against an applied force. Science 1995. 270:1653-1657,

25

Crocker JC, Grier DG: Methods of digital video microscopy for colloidal studies. J Colloid Interface Sci 1996. 179:298-310.
Describes image analysis techniques useful for precise measurement of colloidal dynamics. Spheres' centroids are located to within 20 nm in the focal plane and tracked at 1/30 sec intervals using conventional NTSC video signals. Sample applications include measurement of colloidal diffusion and interactions between charged spheres using blinking optical tweezers to prepare initial conditions. Straightforward extensions of the methods described make possible measurements of the out-of-plane motions to within 30 nm for full three-dimensional tracking [E. Dufresne and D. G. Grier, unpublished (1997)].

26

Crocker JC, Grier DG: Microscopic measurement of the pair interaction potential of charge-stabilized colloid. Phys Rev Lett 1994. 73:352-355.
First measurement of colloidal electrostatic interactions using blinking optical tweezers.

27

Faucheux LP, Bourdieu LS, Kaplan PD, Libchaber AJ: Optical thermal ratchet. Phys Rev Lett 1995. 74:1504-1507. Early demonstration of directed diffusion using a rapidly scanned optical tweezer to simulate a blinking sawtooth potential.

28

van de Ven TGM: Colloidal Hydrodynamics. San Diego: Academic Press 1989.

29

Crocker J: Measurement of the hydrodynamic corrections to the Brownian motion of two colloidal spheres. J Chem Phys 1997: in press.

30

Batchelor GK: Brownian diffusion of particles with hydrodynamic interaction. J Fluid Mech 1976. 74:1-29.

31

Happel J, Brenner H: Low Reynolds Number Hydrodynamics. Dordrecht: Kluwer 1991.

32

Faucheux LP, Libchaber AJ: Confined Brownian motion. Phys Rev E 1994. 49:5158-5163.

33

Conflicting opinions regarding the nature of electrostatic interactions in charge-stabilized colloidal suspensions are summarized in Jönsson B, Åkesson T, Woodward CE: Theory of interactions in charged colloids in Ordering and Phase Transitions in Colloidal Systems. Edited by Arora AK, Tata BVR. New York: VCH 1996 pp. 295-313; and Smalley MV: Long-range attraction in charged colloids ibid, pp 315-337.

34

Russel WB, Saville DA, Schowalter WR: Colloidal Dispersions. Cambridge: Cambridge University Press 1989.

35

Crocker JC, Grier DG: When like charges attract: The effects of geometrical confinement on long-range colloidal interactions. Phys Rev Lett 1996. 77:1897-1900.
Measurements of long-range electrostatic interactions between pairs of charged colloidal microspheres. Results for isolated pairs indicate a purely repulsive interaction and agree quantitatively with predictions of the DLVO theory. Spheres confined between charged glass walls, however, exhibit a long-ranged attraction inconsistent with the DLVO theory.

36

Risken H: The Fokker-Planck Equation. Springer series in synergetics. Berlin: Springer-Verlag, 2nd edition 1989.

37

Kepler GM, Fraden S: Attractive potential between confined colloids at low ionic strength. Phys Rev Lett 1994. 73:356-359.
First direct measurement of attractive pairwise interaction between charged spheres confined between parallel charged glass walls. The pair potential is extracted from imaging measurements on dilute monolayer suspensions.

38

Carbajal-Tinoco MD, Castro-Román F, Arauz-Lara JL: Static properties of confined colloidal suspensions. Phys Rev E 1996. 53:3745-3749.
Confirmation of the results from reference [37] using liquid structure theory to account for many-body effects.

39

Larsen AE, Grier DG: Melting of metastable crystallites in charge-stabilized colloidal suspensions. Phys Rev Lett 1996. 76:3862-3865.
Observation of long-lived colloidal crystals formed by electrohydrodynamic compression of colloidal fluid.

40

Larsen AE, Grier DG: Like-charge attractions in metastable colloidal crystallites. Nature 1997. 385:230-233.
The structure and dynamics of superheated metastable colloidal crystals are shown to be inconsistent with repulsive pairwise interactions. Optical tweezer interaction measurements show that wall-mediated attractive interactions (see references [35, 37, 38]) cannot account for these crystals' stability. Instead long-range attractive interactions appear to be an intrinsic many-body contribution to the crystals' free energy.

41

Chu X, Wasan DT: Attractive interaction between similarly charged colloidal particles. J Colloid Interface Sci 1996. 184:268-278.
Liquid structure calculation in the mean spherical approximation which suggests a mechanism for many-body attractions in charged colloidal suspensions.

42

Carbajal-Tinoco MD, Grier DG: Attractive colloidal interactions at finite density in the hypernetted chain approximation. preprint 1997.
Liquid structure calculation in the hypernetted chain approximation in which the effective pair potential is shown to cross over to a form resembling the Lennard-Jones potential in accord with measurements in reference [40].

43

Stevens MJ, Falk ML, Robbins MO: Interactions between charged spherical macroions. J Chem Phys 1996. 104:5209-5219.
Extensive molecular dynamics simulation of the distribution of simple ions around a charged macroion in a BCC unit cell. The observation of positive osmotic pressure under all conditions sampled indicates purely repulsive effective ineteractions among neighboring macroions.

44

Dinsmore AD, Yodh AG, Pine DJ: Entropic control of particle motion using passive surface microstructures. Nature 1996. 383:239-242.
First direct measurement of the entropic interaction between a hard sphere and substrate asperities mediated by dissolved polymer. Earlier evanescent wave scattering studies had shown that spheres are attracted to substrates. This study shows that they are also repelled by step edges.

45

Mao Y, Cates ME, Lekkerkerker HNW: Depletion force in colloidal systems. Physica A 1995. 222:10-24.
Excellent overview of depletion forces in colloidal suspensions.

46

Prieve DC, Bike SG, Frej NA: Brownian motion of a single microscopic sphere in a colloidal force-field. Faraday Discuss Chem Soc 1990. 90:209-222.

47

Frej, NA, Prieve DC: Hindered diffusion of a single sphere very near a wall in a nonuniform force field. J Chem Phys 1993. 98:7552-7564.

48

Sasaki K, Koshio M, Misawa H, Kitamura N, Masuhara H: Pattern formation and flow control of fine particles by laser-scanning micromanipulation. Opt Lett 1991. 16:1463-1465.

49

Sasaki K, Koshioka M, Misawa H, Kitamura N, Masuhara H: Optical trapping of a metal particle and a water droplet by a scanning laser beam. Appl Phys Lett 1992. 60:807-809.

50

Heckenberg NR, McDuff R, Smith CP, Rubinsztein-Dunlop H, Wegener MJ: Laser beams with phase singularities. Opt Quantum Elect 1992. 24:S951-S962.
Didactic introduction to the optical vortex state.

51

Simpson NB, Allen L, Padgett MJ: Optical tweezers and optical spanners with Laguerre-Gaussian modes. J Mod Opt 1996. 43:2485-2491.
Demonstration of optical vortex tweezers.

52

Padgett M, Arit J, Simpson N, Allen L: An experiment to observe the intensity and phase structure of Laguerre-Gaussian laser modes. Am J Phys 1996. 64:77-82.
Set of experimental techniques useful for measuring the properties of optical vortices.

53

He H, Heckenberg NR, Rubinsztein-Dunlop H: Optical particle trapping with higher-order doughnut beams produced using high efficiency computer generated holograms. J Mod Opt 1995. 42:217-223.
Comprehensive instructions on how to create optical vortex tweezers.

54

Gahagan KT, Swartzlander GA Jr: Optical vortex trapping of particles. Opt Lett 1996. 21:827-829.
Trapping of low-index particles in a high-index fluid using optical vortex tweezers.

55

He H, Friese MEJ, Heckenberg NR, Rubinsztein-Dunlop H: Direct observation of transfer of angular momentum to absorptive particles from a laser beam with a phase singularity. Phys Rev Lett 1995. 75:826-829.
Trapped CuO particle is observed spinning in an optical vortex trap.

56

Friese MEJ, Enger J, Rubinsztein-Dunlop H, Heckenberg NR: Optical angular-momentum transfer to trapped absorbing particles. Phys Rev A 1996. 54:1593-1596.
Torque applied to a particle trapped in an optical vortex tweezer is shown to be described by the polarization and topological charge quantum numbers.

57

König K, Svaasand L, Liu Y, Sonek G, Patrizio P, Tadir Y, Berns MW, Tromberg BJ: Determination of motility forces of human spermatozoa using an 800 nm optical trap. Cell Mol Bio 1996. 42:501-509.

58

Bar-Ziv R: Instability and ``pearling'' states produced in tubular membranes by competition of curvature and tension. Phys Rev Lett 1994. 73:1392-1395.

59

Bar-Ziv R, Menes R, Moses E, Safran SA: Local unbinding of pinched membranes. Phys Rev Lett 1995. 75:3356-3359.
Optical tweezers are shown to pinch bilayer membranes, causing local unbinding of the bilayer in the region around the pinch.

60

Bar-Ziv R, Frisch T, Moses E: Entropic expulsion in vesicles. Phys Rev Lett 1995. 75:3481-3484.

61

Moroz JD, Nelson P, Bar-Ziv R, Moses E: Spontaneous expulsion of giant lipid vesicles induced by laser tweezers. Phys Rev Lett 1997. 78:386-389.
Molecules forming membranes are predicted to be transformed into micelles or microscopic vesicles under the influence of optical tweezers. These extremely small structures should contribute to the local osmotic pressure in a manner which would drive observed instabilities such as the expulsion of small vesicles from larger parents. The authors report quantitative agreement with trends observed in experiments. This mechanism would explain irreversibility in optical tweezer experiments on membranes and related systems.

62

Seifert U: Morphology and dynamics of vesicles. Current Opinion Colloid Interface Sci 1996. 1:350-357.

63

Nelson P, Powers T, Seifert U: Dynamical theory of the pearling instability in cylindrical vesicles. Phys Rev Lett 1995. 74:3384-3387.

64

Granek R, Olami Z: Dynamics of Rayleigh-like instability induced by laser tweezers in tubular vesicles of self-assembled membranes. J Phys II 1995. 5:1349-1370.

65

Goldstein RE, Nelson P, Powers T, Seifert U: Front propagation in the pearling instability of tubular vesicles. J Phys II 1996. 6:767-796.