Interferometric microscopy

Interferometric microscopy or Imaging interferometric microscopy is the concept of microscopy which is related to holography, synthetic-aperture imaging, and off-axis-dark-field illumination techniques. Interferometric microscopy allows enhancement of resolution of optical microscopy due to interferometric (holographic) registration of several partial images (amplitude and phase) and the numerical combining.

Combining of partial images

In interferometric microscopy, the image of a micro-object is synthesized numerically as a coherent combination of partial images with registered amplitude and phase For registration of partial images, the conventional holographic set-up is used, with the reference wave, which is usual for the optical holography. The multiple exposition allows the numerical emulation of a large Numerical Aperture objective, at moderate values of the Numerical Aperture of the objective used to register partial images. Similar techniques allows scanning and precise detection of small particles. As the combined image keeps both amplitude and phase information, the interferometric microscopy can be especially efficient for the phase objects, allowing detection of light variations of index of refraction, which cause the phase shift or the light passing through for a small fraction of a radian.

Non-optical waves

Although the Interferometric microscopy has been demonstrated only for optical images (visible light), this technique may find application in high resolution atom optics, or optics of neutral atom beams (see Atomic de Broglie microscope), where the Numerical aperture is usually very limited .

See also

• Holography
• Numerical Aperture
• Raman microscope
• Diffraction limited