Differential Interference Microscopy is an advanced microscopy technique that utilises Differential Interference Contrast (DIC) to enhance the contrast of a sample to enable the observation of its fine structure.

Differential interference microscopy system components:

Differential interference microscopy systems are mainly composed of a polariser, a DIC prism (usually a quartz Wollaston prism), an objective lens, and a detector. These components work together to polarise, decompose, interfere and detect light.

Principle of Differential Interference Microscopy

1, the generation and decomposition of polarised light: the illumination beam (unpolarised light) first passes through the polariser, linear polarisation occurs. Then, the polarised light is reflected to the DIC prism through the plane mirror, and is decomposed into two beams of light with a small angle in the direction of polarisation.

2, the passage of light and interference: these two beams of light through the objective lens, after reaching the sample box carrier stage. Due to the different thickness and refractive index of the sample at different locations, the two beams of light in the sample through the neighbouring areas will produce optical range difference. Then, these two beams of light waves and through the objective lens after the focal plane of the installation of the prism, was combined into a beam of light.

3, the formation of the interference image: Finally, the combined beam of light through the detector. In the detector, the two perpendicular beams of light are synthesised into the same polarisation direction, which causes the two to interfere, resulting in enhanced or darkened images. These images ultimately form the eyepiece image for the observer.

Differential Interference Microscopy System Features

1. High resolution: The resolution of differential interference microscopy is one order of magnitude higher than that of ordinary light microscopy, enabling observation of finer surface structure and morphological changes.

2. High precision: The technique achieves a variety of optical range difference measurements by adjusting the relative phase difference, thus obtaining finer surface topography information.

3. Non-contact and non-destructive: Differential Interference Microscopy does not require contact with the sample, avoiding damage and contamination of the sample, making it ideal for observation and research of biological and medical samples.

Differential Interference Microscopy Applications

In life sciences, it can observe cell morphology and structure, as well as the morphology and interactions of biomolecules and proteins; in the semiconductor industry, it can be used to monitor the surface accuracy of semiconductor chips on-line through non-contact measurement.