An indigenous laser light scattering spectrometer is being developed for the studies of biological cells, macromolecules and
their interactions. A laboratory spectrometer is used and modified as scattering arm, Turn Table and Collimating arm. Both
the arms have polarizers, one acting as polarizer and the other as analyzer. The scattered light from the scattering cell is
analyzed by an analyzer and is fed to a PMT and a photon counting module. Except for the PMT all the accessories are
being fabricated indigenously. The studies are based initially on the studies of red blood cells. Studies are focused on for
their single particle and their aggregation behavior. Using the ORT program developed by Otto Glatter the morphology of
red blood cells will be analyzed.
Samarium ion doped in rare earth crystals are spectroscopically interesting system since samarium has
many atomic transitions in the visible range. Single crystals of samarium doped CdF2 has been studied
for its non linear behavior using the home made z-scan set up. The Z-scan technique is a simple
experimental set up which can rapidly measures both nonlinear absorption and Non linear Refraction.
This technique is versatile yet is highly sensitive and has gained rapid acceptance by the nonlinear
optics community as a standard technique for measuring the non linear susceptibility χ(2) or the χ(3)
according as the media is a χ(2) system or the χ(3) system.
When a surface is illuminated with a coherent light such as a laser beam, speckle pattern consisting of bright and dark
regions is observed. It depends on the surface parameters and carries important information about the roughness of the
surface. Various methods and techniques are employed for the determination of surface roughness parameters using
other experimental techniques. In this paper, an experimental approach for surface roughness evaluation based on the
speckle pattern imaging has been attempted by a simple configuration of setup consisting laser and CCD camera .The
speckle image is processed by ImageJ software and the surface parameters like skewness, kurtosis and histogram have
been studied. The technique reported here has a great potential for precise and non-contact optical measurements of
rough surfaces.
Static laser light scattering technique has been used to study the aggregation of red blood cells in plasma with dextran in it in different concentrations. The radius of gyration, the structure factor and the fractal dimension are determined for the clusters using the method given by Sorensen et al for the fractal clusters.
Antigoat IgG raised in rabbit has been used to study its aggregation with goat antigen and the cluster formation is studied using laser light scattering. A (chi) 2 fitting method is used to fit the experimentally determined scattered intensity with the theoretically calculated scattered intensity. Scattered intensity is theoretically computed using a radial distribution function of the rD-3 form. The static structure factor S(q,Rg), the radius of gyration (Rg), and the correlation function ((xi) ) are determined.
A homemade static light scattering set-up has been used to study scattering of spherical polystyrene particles (polyballs) and bacterial strains. The polyballs are of different sizes and of spherical shape. Bacterial strains are thin rods and of different sizes. Unpolarized, linearly polarized, and circularly polarized light is used in our studies. The relation between size, shape, and the state of polarization of the incident light on scattering is studied experimentally. The polarization ratio and the scattering ratio are determined for the macromolecules.
The laser light scattering technique has been used to study the aggregation process in blood platelets (P.R.P. and washed platelets used). Insulin has been used as the agonist and the fractal dimension determined. Aggregation is studied in the light of recent theories on aggregation mechanism. The structure factor for platelets has been determined.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.