Abstract:
Two diode lasers with optical spectroscopic properties for absorption
and emission spectroscopy have been used as sources in the study of
economically important biological materials. In the emission spectroscopy a
fluor sensor with a diode lasing at 396 nm was used to conduct in-vivo and invitro
water-stressed study on the leaves of male and female plants by recording
their chlorophyll fluorescence induction kinetics at the red and far-red bands as
well as their ratios. Using the cWorophyll fluorescence induction kinetics
curves in combination with multivariate data analysis method, discrimination
and classification models were formulated which made it possible to
differentiate and classify the sexes of the nutmeg plant which can be used as a
tool for the early sex prediction of the plant. In the absorption spectroscopy
molecular oxygen in some fruits and wood species were probed by means of
GAs in Scattering Medium Absorption Spectroscopy (GASMAS) technique
using a continuous diode laser emitting at 760 nm. The wavelength modulation
second derivative absorption signals of the oxygen gas were measured relative
to their direct absorption signals and a ratio established. This ratio was found to
be directly proportional to the gas concentration in the scattering medium
under study. For the wood the equivalent optical path lengths in different
directions reflected its anisotropic nature while the differences in equivalent
optical path length was found to relate to their densities. The different time
constants obtained for the fruits and wood species is a potential technique for
identifying and characterizing these species.
