Introduction
The optical microscope is a widely used tool in modern scientific research, medicine, and the industrial world. This magnifying instrument is used for a variety of different tasks, from examining bacteria to conducting industrial product inspections. One form of the optical microscope -- the polarization microscope -- utilizes light polarized in different directions in order to enhance the resolution and contrast of the images produced by the device.
History
The soon-to-be-inventors of the optical microscope researched Hebrew texts in 1609 to develop their device. During this period of development, the Dutch father-son team of Hans and Zacharias Jansen created a single-lens device with which they could observe objects in detail. Shortly thereafter, in 1619 Italian scientist Galileo Galilei took the first optical microscope photo of a bees leg.
In 1873 Canadian scientists Joseph Jackson Lister invented his compound light microscope, which allowed for greater magnification and quality of observations than ever before. Since then, the optical microscope has undergone numerous design changes and modifications, including the addition of polarized light.
Principles of a Polarization Microscope
A normal optical microscope consists of an eyepiece lens and an objective lens. These paired lenses use visible light to magnify an image so that details can be seen that the naked eye is unable to detect.
The polarization microscope builds on this basic design by adding an analyzer, a polarizing filter, and a compensator. The polarizer and the compensator can both be adjusted in order to change the angle at which the light is entering the sample. This manipulated angle enables observers to see fine details that might be blurred or washed away by the angle of normal light. Difference in refractive indexes are accentuated and stunning contrast in color, texture, and size is produced.
Uses of a Polarization Microscope
The polarization microscope is useful in a variety of applications. In medicine and clinical laboratories, it is invaluable in determining the difference between different microorganisms. Because of the increased contrast and detail, a polarized microscope can help scientists differentiate between cell types and other organisms that may otherwise look the same under normal lighting.
Additionally, the polarization microscope is useful in industrial inspection as a way to detect defects such as scratches, flaws, stress marks, cracks, and other imperfections in a variety of materials. The microscope enables materials to be examined in detail for any defects, leading to enhanced quality control in the production of materials.
Conclusion
The polarization microscope is an important tool in the medical, scientific, and industrial worlds, enabling detailed observations and quality control measures. By manipulating light to come in at different angles and using a variety of filters, this device helps increase contrast and provide a better view of microscopic organisms and materials.
