These limitations have overcome to some extent by specific microscopy techniques that can non-invasively increase the contrast of the image. In general, these techniques make use of differences in the refractive index of cell structures.

Zinc Selenidetransmission spectrum

The waves that associate the electrons has smaller wavelength. Then we can use electrons using an electron microscope. Electron microscopes can be used to visualise viruses, molecules and even individual atoms.

Zinc seleniderefractive index

In the 1870s, Ernst Abbe explained why the resolution of a microscope is limited. Since the microscope uses visible light and visible light has a set range of wavelengths. The microscope can't produce the image of an object that is smaller than the length of the light wave. Any object that’s less than half the wavelength of the microscope’s illumination source is not visible under that microscope. Light microscopes use visible light.

Live cells generally lack sufficient contrast to be studied successfully, internal structures of the cell are colourless and transparent. The common way is to increase contrast by different structures with selective dyes, but it often involves killing and fixing the sample.

MILLAR, Neil – WHITE, Ian. Microscopy [online]. The last revision 2004-06-18, [cit. 2012-12-09]. .

Optical Microscope uses system of lenses and visible light to sharply magnify small detailed samples which is projected directly to the eye.

Zinc selenide windowprice

The University of Waikato. Magnification and resolution [online]. [cit. 2012-12-09]. .

Zinc Selenide (ZnSe) Windows are ideal for a wide variety of infrared applications including thermal imaging, FLIR, and medical systems. This chemically vapor deposited material has wide usage in high power CO2 laser systems because of its low absorption coefficient and high resistance to thermal shock. Zinc Selenide (ZnSe) is a relatively soft material that scratches easily and it is not recommended in harsh environments because its Knoop Hardness is only 120. When handling, apply uniform pressure and wear Latex finger cots or gloves to prevent contamination.