Optimizing multiple beam interferometry in the surface forces apparatus: Novel optics, reflection mode modeling, metal layer thicknesses, birefringence, and rotation of anisotropic layers.

Multiple beam interferometry (MBI) evolved as a powerful tool for the simultaneous evaluation of thin film thicknesses and refractive indices in Surface Forces Apparatus (SFA) measurements. However, analysis has relied on simplifications for providing fast or simplified analysis of recorded interference spectra. Here, we describe the implementation of new optics and a generalized fitting approach to 4 × 4 transfer matrix method simulations for the SFA. Layers are described by dispersive complex refractive indices, thicknesses, and Euler angles that can be fitted, providing modeling for birefringent or colored layers. Normalization of data by incident light intensities is essential for the implementation of a fitting approach. Therefore, a modular optical system is described that can be retrofit to any existing SFA setup. Real-time normalization of spectra by white light is realized, alignment procedures are considerably simplified, and direct switching between transmission and reflection modes is possible. A numerical approach is introduced for constructing transfer matrices for birefringent materials. Full fitting of data to the simulation is implemented for arbitrary multilayered stacks used in SFA. This enables self-consistent fitting of mirror thicknesses, birefringence, and relative rotation of anisotropic layers (e.g., mica), evaluation of reflection and transmission mode spectra, and simultaneous fitting of thicknesses and refractive indices of media confined between two surfaces. In addition, a fast full spectral fitting method is implemented for providing a possible real-time analysis with up to 30 fps. We measure and analyze refractive indices of confined cyclohexane, the thickness of lipid bilayers, the thickness of metal layers, the relative rotation of birefringent materials, contact widths, as well as simultaneous fitting of both reflection and transmission mode spectra of typical interferometers. Our analyses suggest a number of best practices for conducting SFA and open MBI in an SFA for increasingly complex systems, including metamaterials, multilayered anisotropic layers, and chiral layers.

[1]  M. Balabajew,et al.  A 3-mirror surface force balance for the investigation of fluids confined to nanoscale films between two ultra-smooth polarizable electrodes. , 2018, The Review of scientific instruments.

[2]  B. Zappone,et al.  Multiple-beam optical interferometry of anisotropic soft materials nanoconfined with the surface force apparatus. , 2018, The Review of scientific instruments.

[3]  J. Israelachvili,et al.  In situ nano- to microscopic imaging and growth mechanism of electrochemical dissolution (e.g., corrosion) of a confined metal surface , 2017, Proceedings of the National Academy of Sciences.

[4]  E. Schubert,et al.  Anisotropic contrast optical microscope. , 2016, The Review of scientific instruments.

[5]  G. Drazer,et al.  Micropatterned charge heterogeneities via vapor deposition of aminosilanes. , 2015, Langmuir : the ACS journal of surfaces and colloids.

[6]  J. Israelachvili,et al.  Real-time intermembrane force measurements and imaging of lipid domain morphology during hemifusion , 2015, Nature Communications.

[7]  T. Kuhl,et al.  Analyzing refractive index profiles of confined fluids by interferometry. , 2014, Analytical chemistry.

[8]  S. Raman,et al.  Angstrom-resolved real-time dissection of electrochemically active noble metal interfaces. , 2014, ACS nano.

[9]  T. Kuhl,et al.  Thickness and refractive index of DPPC and DPPE monolayers by multiple-beam interferometry , 2014, Analytical and Bioanalytical Chemistry.

[10]  Jacob N. Israelachvili,et al.  Interactions and visualization of bio-mimetic membrane detachment at smooth and nano-rough gold electrode surfaces , 2013 .

[11]  J. Israelachvili,et al.  The electrochemical surface forces apparatus: the effect of surface roughness, electrostatic surface potentials, and anodic oxide growth on interaction forces, and friction between dissimilar surfaces in aqueous solutions. , 2012, Langmuir : the ACS journal of surfaces and colloids.

[12]  J. Israelachvili,et al.  Hydrophobic forces, electrostatic steering, and acid-base bridging between atomically smooth self-assembled monolayers and end-functionalized PEGolated lipid bilayers. , 2012, Journal of the American Chemical Society.

[13]  J. Gerasimov,et al.  Combined optical and acoustical method for determination of thickness and porosity of transparent organic layers below the ultra-thin film limit. , 2011, The Review of scientific instruments.

[14]  M. Schubert,et al.  Virtual separation approach to study porous ultra-thin films by combined spectroscopic ellipsometry and quartz crystal microbalance methods , 2011 .

[15]  M. Schubert,et al.  In-situ monitoring of alkanethiol self-assembled monolayer chemisorption with combined spectroscopic ellipsometry and quartz crystal microbalance techniques , 2011 .

[16]  F. Mugele,et al.  Instability of confined water films between elastic surfaces. , 2010, Langmuir : the ACS journal of surfaces and colloids.

[17]  J. Israelachvili,et al.  Recent advances in the surface forces apparatus (SFA) technique , 2010 .

[18]  Ida Z. Kozma,et al.  Direct measurement of the group-velocity mismatch and derivation of the refractive-index dispersion for a variety of solvents in the ultraviolet , 2005 .

[19]  R. Horn,et al.  Extending the surface force apparatus capabilities by using white light interferometry in reflection , 2003 .

[20]  J. Vaníček,et al.  The extended surface forces apparatus. Part III. High-speed interferometric distance measurement , 2003 .

[21]  N. Spencer,et al.  Density Fluctuations Under Confinement: When Is a Fluid Not a Fluid? , 2001, Science.

[22]  M. Heuberger.  The extended surface forces apparatus. Part I. Fast spectral correlation interferometry , 2001 .

[23]  M. Salmeron,et al.  Dynamics of layering transitions in confined liquids. , 2000, Physical review letters.

[24]  G. Somorjai,et al.  Structure of confined films of chain alcohols , 2000 .

[25]  M. Majewski,et al.  Optical properties of metallic films for vertical-cavity optoelectronic devices. , 1998, Applied optics.

[26]  P. Ciddor.  Refractive index of air: new equations for the visible and near infrared. , 1996, Applied optics.

[27]  Schubert,et al.  Polarization-dependent optical parameters of arbitrarily anisotropic homogeneous layered systems. , 1996, Physical review. B, Condensed matter.

[28]  T. Vanderlick,et al.  Extended Spectral Analysis of Multiple Beam Interferometry: A Technique To Study Metallic Films in the Surface Forces Apparatus , 1994 .

[29]  L. Chau,et al.  Composition and structure of spontaneously adsorbed monolayers of n-perfluorocarboxylic acids on silver , 1990 .

[30]  M. Clarkson.  Multiple-beam interferometry with thin metal films and unsymmetrical systems , 1989 .

[31]  W. M. Moore,et al.  Oxidation of silver films by atomic oxygen , 1988 .

[32]  J. Israelachvili,et al.  Molecular layering of water at surfaces and origin of repulsive hydration forces , 1983, Nature.

[33]  J. Israelachvili,et al.  The hydrophobic interaction is long range, decaying exponentially with distance , 1982, Nature.

[34]  J. Israelachvili,et al.  Direct experimental verification of the Kelvin equation for capillary condensation , 1979, Nature.

[35]  J. Israelachvili,et al.  Measurement of forces between two mica surfaces in aqueous poly(ethylene oxide) solutions , 1979, Nature.

[36]  Jacob N. Israelachvili,et al.  Thin film studies using multiple-beam interferometry , 1973 .

[37]  G. M. Hale,et al.  Optical Constants of Water in the 200-nm to 200-microm Wavelength Region. , 1973, Applied optics.

[38]  David Tabor,et al.  The measurement of van der Waals dispersion forces in the range 1.5 to 130 nm , 1972, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[39]  David Tabor,et al.  The direct measurement of normal and retarded van der Waals forces , 1969, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[40]  D. Tabor,et al.  Surface Forces: Direct Measurement of Normal and Retarded van der Waals Forces , 1968, Nature.

[41]  I. Malitson.  Interspecimen Comparison of the Refractive Index of Fused Silica , 1965 .

[42]  S. Tolansky.  Interferometric evaluation of thicknesses of thin films , 1950 .

[43]  J. Israelachvili,et al.  Real-Time Monitoring of Aluminum Crevice Corrosion and Its Inhibition by Vanadates with Multiple Beam Interferometry in a Surface Forces Apparatus , 2015 .

[44]  T. Kuhl,et al.  UC Davis UC Davis Previously Published Works Title Analyzing refractive index profiles of confined fluids by interferometry part II : Multilayer and asymmetric systems , 2014 .

[45]  J. Israelachvili,et al.  Measurement of forces between two mica surfaces in aqueous electrolyte solutions in the range 0–100 nm , 1978 .

[46]  A. Bailey,et al.  Measurement of refractive index and dispersion of mica, employing multiple beam interference techniques , 1965 .