NIP REPORT January 2006- May 2007 - The UP College of Science ...

shifter has been a workhorse in frequency conversion due to its high conversion of the pump
beam to the Raman components. We present, for the first time to the best of our knowledge,
evaluation of the images obtained under several parameters such as laser excitation energy,
hydrogen gas pressure and focusing geometry.
Analysis of Laser produced plasma
W. Garcia
Ph.D.: J. Gabayno
B.S: M. Paguio, P. Arevalo
The integration of lasers into research laboratories has led to the investigation of pulsed laser
interaction with matter at laser intensities sufficient to transform matter into plasma. The stream
of electrons, ions, excited and neutral atoms as well as other ejected materials produced via such
laser-matter interaction is referred to as Laser Produced Plasma (LPP). In our group, we
specialize on the characterization of LPP particularly by obtaining the relevant plasma
parameters like the electron temperature and electron density via optical diagnostic methods
particularly time resolved optical emission spectroscopy. To date, the study of LPP has attracted
a lot of attention. The continuing interest in this field is driven by its scientific and technological
applications which includes pulsed laser deposition, spectrochemical or mass analysis of
samples. This study aims to investigate the temperature and electron density of a laser produced
hydrogen, titanium and aluminum plasma.
Phase retrieval using a volume speckle field
P. Almoro
B.S.: V. Balois, M. Maallo, Edelyn Reyes
The technique allows measurements of the phase and amplitude of wave fields from rough
objects. Applications include wavefront sensing and coherent metrology. The main advantage of
this new phase retrieval method is the simple setup because it does not require a separate
reference beam (as in holography). Thus the setup is inexpensive to build and is not tedious to
implement. The essential difference compared to conventional phase retrieval methods is that the
source of information in this technique is the whole volume of the sampled field and not just the
usual two measurement planes. The accuracy of the calculated phase using SBMIR technique,
therefore, is more reliable and converges faster.
Applications of a portable shearography system
P. Almoro
M.S.: F. Catalan
Conventional speckle interferometry is sensitive to displacement of a point on the object’s
surface. Shearography, on the other hand, is sensitive to strain and surface slope measurements.
Due to its sensitivity to the derivative of the displacement, it is unaffected by rigid body motion,
which makes it more appealing for vibrational and structural analysis. Recent studies on
shearography have geared towards its use in other applications such as art conservation and high
temperature measurements. A portable shearography set-up for industrial on-site inspection is yet
to be achieved.
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