Refractive index microscopy

Brewster angle microscopy takes advantage of the reflectivity behavior of light at an interface. This method relies on the fact that light passing from a material of lower refractive index, no into a medium of higher index i will have... 

Microscopy (qv) plays a key role in examining trace evidence owing to the small size of the evidence and a desire to use nondestmctive testing (qv) techniques whenever possible. Polarizing light microscopy (43,44) is a method of choice for crystalline materials. Microscopy and microchemical analysis techniques (45,46) work well on small samples, are relatively nondestmctive, and are fast. Evidence such as sod, minerals, synthetic fibers, explosive debris, foodstuff, cosmetics (qv), and the like, lend themselves to this technique as do comparison microscopy, refractive index, and density comparisons with known specimens. Other microscopic procedures involving infrared, visible, and ultraviolet spectroscopy (qv) also are used to examine many types of trace evidence. 

Optical properties of fibers are measured by light microscopy methods. ASTM D276 describes the procedure for fiber identification using refractive indexes and birefringence. Other methods for determining fiber optical properties have been discussed (3,38—44). However, different methods of determining optical properties may give different results (42). 

Figure 17 Fluorescence microscopy images of a standing 2.5-n.m-long DMPOPOP-loaded zeolite L crystal upon excitation at 330-385 nm and observed with a cutoff filter (410 nm) (a) in air and (b) in a refractive-index-matching solvent.

Uses. Gauge fluid solvent refractive index liquid in microscopy... 

Uses. Chemical intermediate in microscopy because of its high refractive index... 

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