Andres H. La Rosa 
Associate Professor of Physics
 
              Office  Phone :     (503) 725 - 8397 
Lab :     Science  Building 1
    Room 30
     E-Mail :     andres@pdx.edu



___________________________________________________________________________________________________________________

Research interests      

   Dr. La Rosa’s research focuses on the fabrication and characterization of nanomaterials, which involve  i)  the  development of high-resolution
   imaging/metrology tools (
t-NSOM) and SANM)  for characterizing dynamic process in mesoscopic systems, and ii) self-assembly fabrication of polymer
   materials with stimili responsive characteristics (PEN).

   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 microscope to also characterize elastic materials properties.  The resulting "
Shear-force/Acoustic Near-field Microscope" (SANN-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.

___________________________________________________________________________________________________________________
 
T
eaching

  General Physics:                       PH-211                 PH-222 /212           PH-213   
   
  Experimental Physics:           PH-314                 PH-315
  

  Applied Optics:                          PH-564/464        ECE 594        
 
  Nanomaterials Fabrication                        NanoFab-2006      
                                                                     
NanoFab-2007  
                                                                     Nanomaterials Fabrication  Spring-2011  

  Introduction to Quantum Mechanics:        PH 411/511              ECE 598

 
  Seminars      Physics Seminar - 2009          PH-407/507/607 (2009)     
                       PNNA-Seminar - 2011         
Multidisciplinary Topics on Science and technology
  


__________________________________________________________________________________________________________________________
Publications

Xiaohua Wang, Xin Wang, Rodolfo Fernandez, Mingdi Yang, and Andres La Rosa,  "Nanolithography on responsive materials," 
J. Nanosci. Lett. 2, 23 (2012).

A. H. La Rosa, N. Li, R. Fernandez, X. Wang, R. Nordstrom, and S. K. Padigi, “Whispering-gallery acoustic sensing: Characterization of mesoscopic films
      and scanning probe microscopy applications,” Rev.Sci.Instrum.82, 093704 (2011).
                      This paper was select
ed by the Virtual Journal of Nanoscale Science & Technology, Oct 3, 2011.     
                     
Vir. J. Nan. Sci & Tech 24, Issue 14/ STRUCTURAL PROPERTIES SECTION (2011) 

R. Fernandez, X. Wang , and A. H. La Rosa, “Acousto Characterization of Fluid-like Mesoscopic Films under Shear,” Proceedings of the IEEE Nano 2011
       Conference (Portland, OR 2011), in press.

M. Hopkins, M. K. Morakinyo, S. Rananavare, A. H. La Rosa, and J. L. Freeouf, “Coaxial Tips for Infrared NSOM ,” Proceedings of the IEEE Nano 2011
       Conference (Portland, OR 2011), in press.


A. La Rosa and M. Yan. “Proton-Fountain Electric-Field-Assisted Nanolithography (PEN),” Chapter 8 in Tip-Based Nanofabrication: Fundamentals and Applications,
      Springer: New York, Ed. A. A. Tseng, p. 299-324 (2011).

Xiaohua Wang, Xin Wang, R. Fernandez, L. Ocola, M. Yan, and A. La Rosa; “Electric Field-Assisted Dip-Pen Nanolithography on Poly(4-vinyl Pyridine) Films,”
      ACS Appl. Mater. Interface 2, 2904–2909 (2010).

C. Maedler, H. Graaf, S. Chada, M. Yan, and A. La Rosa, "Nano-structure Formation Driven by Local Protonation of Polymer Thin Films",
      Proc. SPIE 7364, 736409-1 – 736409-8 (2009).

C. Maedler, S. Chada, X. Cui, M. Taylor, M. Yan, and A. La Rosa, “
Creation of nanopatterns by local protonation of P4VP via dip pen
      nanolithography.” J. Appl. Phys. 104, 014311 (2008).

S. K. P
adigi, K. Aasante, R. K. K. Reddy, V. S. R. Kovvuri, A. La Rosa, and S. Prasad, “Micro-photonic cylindrical waveguide based protein biosensor,” SPIE
      Proceedings, Integrated Optics: Devices, Materials and Technologies XI, Ed: Y. Sidrorin and C.A. Waechter, SPIE 6475, 6475031 –  647503-10 (2007).

S. K. Padigi, K. Asante,
V. S. R. Kovvuri, R. K. K. Reddy, A. La Rosa and S. Prasad, “Micro-photonic cylindrical waveguide based protein biosensor,”
      Nanotechnology 17, 4384 (2006).

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 "Nanofabrication: Technologies, Devices, and Applications II,” Warren Y. Lai, L. E. Ocola, Stanley Pau Eds., Symposium
  in Optics East 2005, Boston, MA. Proc. SPIE
6002,  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).
                      Paper was selected by the Virtual Journal of Nanoscale Science & Technology
                     
Vir. J. Nan. Sci. & Tech. / Volume 12 / Issue 13 / IMAGING SCIENCE AND TECHNOLOGY

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 microscopy (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 Conference 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. Proc406, 189-194 (1996).

A. H. La Rosa, B. I. Yakobson and 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.
      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 (1995).

A. H. La Rosa, C. L. Jahncke, H. D. Hallen, "Time as a contrast mechanism in near-field imaging", Ultramicroscopy 57, 303 (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, National University
      of Engineering,  Lima-Peru, 1985.
__________________________________________________________________________________________________________________________

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

                                      .
Sholarship Opportunities
 

  NSF  Division of Undergraduate Education

  National Defense Science and Engineering   Graduate Fellowships

   SME Education Foundation (Undergraduate and graduate students)

  Delta Gamma Foundation(Undergraduate and graduate students)

  Inventors Competition   ( $ 20,000 cash prize)

  List of scholarships

                                      .
General Information

       The Top Physicists in History

      Definition of the  meter

     Bjoern's Thesis    
                                      .
Research group: Current Projects      



Portland State University
last modified December, 2005