Hologram

Definition

A hologram is a three-dimensional image formed by the interference of light beams from a laser or other coherent light source. It captures both the intensity and phase information of light waves reflected from an object, allowing for a detailed and realistic representation.

5 Must Know Facts For Your Next Test

1. Holograms are created using the principle of interference and diffraction of light.
2. The process involves splitting a laser beam into two paths: the object beam that illuminates the subject and the reference beam that does not.
3. When these two beams intersect, they create an interference pattern recorded on a photographic plate or digital sensor.
4. Upon illumination with coherent light, this recorded pattern reconstructs the 3D image, making it visible to the naked eye.
5. Atomic excitation and de-excitation processes play crucial roles in generating coherent light sources like lasers used in holography.

Review Questions

• What fundamental principles are employed in creating a hologram?
• How does a laser contribute to the formation of a hologram?
• Explain how atomic excitations and de-excitations are related to producing coherent light necessary for holography.

Related terms

Interference:

The phenomenon where two waves superpose to form a resultant wave of greater, lower, or the same amplitude.

Diffraction:

The bending of light around obstacles and the spreading out of light waves when they pass through small openings.

Coherent Light:

Light in which waves maintain a constant phase relationship with each other over time, often produced by lasers.