Modified Abbe Refractometers Lab Report

2.1 Introduction. The measurement of the RI. of liquids is a significant work in science and engineering.. Transmission or reflection disclosures near critical angles linked to TIR. are common ways in RI. measurements. Modified Abbe refractometers and commercial Abbe refractometers are instruments for measuring the RI. of a sample using those ways. The RI. resolution of those instruments. roughly extent from 10−4 to 10−5 depending on their cost and complexity. RI. of muddy colloidal liquids were measured by the transmission mode near the critical angle. using a modified Abbe refractometer [56]. Also RI.. of absorbing and turbid liquids. were measured by reflection methods near the critical angle [57]. To accommodate and heterogeneous
A fibre with a large value of V. supports many modes., however for V < 2.4 all modes except for the HE11 mode reach cut-off. That fibres support a single-.mode and are called single-.mode fibre, supporting only the HE11 mode, familiar as the fundamental mode of the fibre.. The lowest order mode HE11 is denoted LP01. The single-.mode situation is determined by the value of V. at which the TE01 and .TM01 arrive to cut off and hence the V value is under than 2.405 [63].
2.5 Polarization mode dispersion. Polarization mode dispersion .(PMD) has related to the differential group delay (DGD)., the time difference in the group delays between two orthogonal polarized modes., which causes pulse spreading in digital systems and distortions in analogue systems.. In ideal circular symmetric fibers., the two polarization modes propagate with the same velocity.. However, real fibers cannot be perfectly circular and could undergo local stresses.; consequently., the propagating ray has split into two polarization modes (Figure 2-4)[68].
Figure (2-4):"DGD due to the two polarization modes propagating at different velocities".
2.6 Applications of Optical