Andres H. La Rosa

Andres H. La Rosa
Associate Professor of Physics

Office Phone :	(503) 725 - 8397
Office :	Science Building 2 Room 418
E-Mail :	andres@pdx.edu

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Research interests

   Dr. La Rosa’s research focuses on the development of high-resolution imaging/metrology tools for characterizing dynamic process in mesoscopic systems.
   Semiconductor Materials Characterization:
      His “Lifetime Near-field Scanning Optical Microscope" (t-NSOM) uses a purely optical pump-probe method for mapping semiconductors’ surfaces
   according to their carrier-lifetime (the average time that excited carriers take to return to equilibrium). Here, the values of t (which are affected by
   the presence of defects) reflect materials quality. The near-field optical approach allows better lateral spatial resolution than conventional techniques.
Characterization of Mesoscopic Films and Subsurface Material Properties
    More recently Dr. La Rosa has incorporated ultrasonic sensing into the NSOM microscope, which enhances the versatile characteristics of the new micros-
cope to also characterize elastic materials properties. The resulting "Shear-force/Ultrasonic Near-field Microscope" (SUN-M) is being used for a) Inves-
      tigating the quite different (from the bulk) dynamic displayed by fluid-like films when subjected to mesoscopic confinement and while in intimate contact with
      two sliding solid boundaries; this studies have implications in nanotribology (friction studies at the nanometer scale); as well as b) for imaging subsurface material
properties.
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Teaching

   General Physics:    PH-211             PH-222 /212       PH-213

   Experimental Physics:   PH-314            PH-315

   Applied Optics:                 PH-564/464

   Fabrication and Characterization of Nanomaterials:        NanoFab-2006    NanoFab-2007

Introduction to Quantum Mechanics: PH 411/511

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Publications

A. H. La Rosa, N. Li, and K. Asante, “The ultrasonic/shear-force microscope: a metrology tool for surface science and technology," Invited Paper, in "Nanofabri-
cation: Technologies, Devices, and Applications II,” Warren Y. Lai, L. E. Ocola, Stanley Pau Eds., Symposium in Optics East 2005, Boston, MA. Proc.
SPIE 6002, p. 163-170 (2005).

X. Cui, A. H. La Rosa, “Investigation of the probe-sample interaction in the ultrasonic/shear force microscope: The phononic friction mechanism.” Appl. Phys.
         Lett. 87, 231907 (2005).

A. H. La Rosa, R. Nordstrom, X. Cui, J. McCollum,"The Ultrasonic/shear-force microscope: Integrating ultrasonic sensing into a near-field scanning optical
     microscope," Rev. Sci. Instrum. 76, 093707 (2005).

R. Chandra Sikakollu, L. Meekisho, A. H. La Rosa, “Coupled Field Analyses in MEMS with Finite Element Analysis.” Journal of Heat Transfer, 127, 34
         (2005).

E. E. van Dyk, A. Karoui, A. H. La Rosa, and G. Rozgonyi, “Near-field scanning optical microscopy for characterization of photovoltaic materials,” Phys.
   Stat Sol. (c) 1, pp. 2292– 2297 (2004).

B. Biehler and A. H. La Rosa, “High frequency-bandwidth optical technique to measure thermal elongation time responses of near-field scanning optical micros-
copy (NSOM) probes,” Rev. Sci. Instrum. 73, 3837-40 (2002).

H. P. Chiang, A. H. La Rosa, P. T. Leung, K. P. Li, and W. S. Tse; "Optical spectroscopy for single-molecules near a microstructure at varying substrate
temperatures;" Optics. Commun. 205, 343-350 (2002).

A. H. La Rosa and H. Hallen, “A compact method for optical induction of proximal probe heating and elongation”, Appl. Optics 41, 2015-9 (2002).

H. D. Hallen and A. H. La Rosa, "Near-Field Scanning Optical Microscopy as an Imaging Tool for Silicon Carrier Processes," Proc. of International Conferen-
ce on Silicon Dielectric Interfaces, Research Triangle Park, NC 25-27, February 2000.

A. H. La Rosa, B. I. Yakobson and H. D. Hallen, "Optical imaging of carrier dynamics with sub-wavelength resolution", Appl. Phys. Lett. 70, pp 1656 (1997).

A. H. La Rosa, B. I. Yakobson and H. D. Hallen, "Imaging of Silicon Carrier Dynamics with Near-Field Scanning Optical Microscopy", Mat. Res. Soc. Symp.
Proc. 406, p. 189-194 (1996).

A. H. La Rosa, B. I. Yakobson abd H. D. Hallen, "Origins and effects of thermal processes on near-field optical probes", Appl. Phys. Lett. 67, 2597 (1995).

A. H. La Rosa, C. Jahncke, H. Hallen, "Time-resolved contrast in near-field scanning optical microscopy of semiconductors", SPIE 2384, pp. 101 (1995).

H. D. Hallen, A. H. La Rosa, C. L. Jahncke, "Near-Field Scanning Optical Microscopy and Spectroscopy for Semiconductor Characterization", Physica Status
Solidi (A) 152, 257-268 (1995).

A. H. La Rosa, C. L. Jahncke, H. D. Hallen, "Time as a contrast mechanism in near-field imaging", Ultramicroscopy 57, pp. 303-8 (1995).

B. I. Yakobson, A. H. La Rosa, M. A. Paesler, H. Hallen, "Thermal/Optical effects in NSOM probes", Ultramicroscopy 61, 179 (1995).

A. H. La Rosa, M. A. Paesler, H. D. Hallen, "Characterization of Semiconductor Surfaces with the Near-Field Scanning Optical Microscope", Precision
Engineering Center, 1994 Annual Report Val. XII, PP. 29-38; North Carolina State University, Raleigh, NC.

A. H. La Rosa, "Computer Simulation of Diffusion Controlled Deposition", Master Thesis, Southern Illinois University at Carbondale, 1990.

<>A. H. La Rosa, "Non-Linear Physics. Solitons and The Inverse Scattering Method", Thesis of Licenciado (Professional thesis),National University of Engineering,
Lima-Peru, 1985.

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Optical micro and nano technologies

Optical MEMS:
First practical Micro_Electro-Optical-Mechanical-Switch built at Bell Labs

Flat mirrors built at UCLA

What is MEMS?

MEMS applications: Dr. K. D. Wise @ The University of Michigan Center for Integrated Microsystems

Bishop's_presentation

DNA in nanostructures at Delft University of Technology - Netherlands

Andres' Near-Field Optical Microscopy Images on Charge Carriers Dynamics

Photonics: Dream of Optical Network realized at Agilent

Link to Scanning Capacitance Microscopy SCM

Other technologies
Unexpected discovery could yield full spectrum solar cell

High-Temperature Superconductivity: Scanning Tunneling Microscope reveals new insights