Related Experiment Video
Updated: Jun 12, 2026

10:28
Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization
Published on: July 5, 2016
Refraction correction in holographic interferometry and tomography of transparent objects.
Applied Optics
|May 22, 2010
Summary
This study compares algorithms for refractive-index field reconstruction. A perturbation approach effectively reduces refraction errors in holographic interferometry, outperforming divergent iterative methods.
Area of Science:
- Optics and Photonics
- Computational Imaging
- Tomographic Reconstruction
Background:
- Tomographic reconstruction of refractive-index fields is crucial for various optical applications.
- Significant refraction poses a major challenge in accurately reconstructing these fields.
- Existing algorithms often struggle with the nonlinear nature of the problem.
Purpose of the Study:
- To review and extend state-of-the-art algorithms for 1-D and 2-D refractive-index field reconstruction.
- To compare the performance of a perturbation approach against iterative procedures in holographic interferometry.
- To identify robust methods for mitigating refraction errors.
Main Methods:
- Numerical simulations of holographic interferometry experiments were conducted.
- A perturbation approach was implemented and evaluated.
- Two iterative reconstruction procedures were tested and compared with the perturbation method.
Main Results:
- Iterative algorithms exhibited divergent behavior in the presented examples, making general conclusions difficult.
- The perturbation technique demonstrated significant power in reducing refraction errors.
- The perturbation method proved easier to implement and faster to run compared to iterative methods.
Conclusions:
- The perturbation approach is a powerful and efficient technique for tomographically reconstructing refractive-index fields with significant refraction.
- Iterative methods, while explored, showed limitations due to nonlinearity and divergence in this context.
- The findings highlight the practical advantages of the perturbation method for holographic interferometry.
Related Concept Videos
Interference and Diffraction
Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other.
Focusing of Light in the Eye
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
Influence of Earth's Curvature and Atmospheric Refraction on Leveling
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance. Over a...
Total Internal Reflection Fluorescence Microscopy
Total internal reflection fluorescence microscopy or TIRF is an advanced microscopic technique used to visualize fluorophores in samples close to a solid surface with a higher refractive index, such as a glass coverslip. TIRF only allows fluorophores in proximity to the solid surface to be excited. When light from a medium with a lower refractive index (such as air) hits the glass coverslip at a critical angle, the light undergoes total internal reflection stead of passing through the glass.

