Polarizing Microscopes: Let’s talk about them!

Beautiful colors created by polarizing microscopes
Source: Unsplash

Polarizing microscopes are amazing, and polarized light microscopy is an essential technique in many laboratories and scientific disciplines. They’re particularly good at examining the nature of crystals in geologic samples and analyzing details in biological structures. In this article, we’ll review some common questions you may have about polarizing microscopes and how to get started yourself.

What are Polarizing Microscopes?

As stated above, polarizing microscopes are used to image transparent or otherwise difficult-to-image specimens and are particularly useful for visualization of materials that are anisotropic and birefringent (meaning it has two refractive indices). What makes polarizing microscopes unique is not their light source but actually the filter that stands between the light source and the specimen.

How do they work?

The key mechanic is a specific filter. These filters help linearly polarize the light from the light source, meaning the light waves are adjusted to shine in a particular direction rather than randomly, as in ordinary light. When this polarized light hits a specimen, one of two outcomes will be achieved: the specimen will either be unaffected, or if the specimen is birefringent, it will split into two beams with different polarizations. A second analyzer filter in the eyepiece blocks out all but one polarization of the light. The result is a much higher contrast image of the specimen which would have been invisible under standard light.

What brands are best?

In addition to being a superior brands for microscopes in general, Leica is also a great brand for polarizing microscopes. Leica polarization microscopes are designed for all polarizing examinations: petrography, mineralogy, structure characterization, asbestos analysis, coal analysis (vitrinite reflection), and examination of liquid crystals. With versatile instrument options, Leica polarizing microscopes are an ideal match for analyzing glass, minerals, plastics, polymers, drugs, textiles, fibers or testing displays in the semiconductor industry.

What are some advantages of using polarizing microscopes?

Polarized light microscopes offer several advantages. First, they are the standard for visual mineralogy. Materials like crystals and fibers are anisotropic and birefringent, which as described above makes them notoriously difficult to image without using a polarizing filter. The microscope provides vital information on refractive index, birefringence, sign of elongation, pleochroism, and angle of extinction. Moreover, polarizing microscopy does not necessarily need the use of dyes, which can make them an ideal choice for when the specimen must remain unaltered for imaging.

Thinking of using polarizing microscopes in your lab? Visit our website for more information or to get in touch with our sales team. Happy viewing!