Trailing Edge

The Whole Picture

  • December 2002
  • By Lisa Scanlon

Holography's microscopic origins.

   

Holography is part of our everyday lives-from a commemorative 3-D Elvis on the cover of TV Guide to the tiny images designed to discourage credit card counterfeiters. Advances such as holographic video (see "Holograms in Motion," TR November 2002) suggest that it will also be a compelling part of our future. All these technologies have their origin in a serendipitous discovery by Dennis Gabor, a Hungarian scientist who was trying to make an improvement to the electron microscope.

The electron microscope, invented in the 1930s, had a resolution power more than a hundred times greater than that of the best light microscopes of the time. However, because the aperture of electron lenses couldn't be increased beyond a certain point, the electron microscope stopped just short of resolving individual atoms. In 1947 Gabor was working at the British Thomson-Houston Company in Rugby, England, speculating on ways to get around this limitation. Gabor thought that perhaps he could take a "bad" picture and then correct it using optical means. Because such a picture would be missing important information-the phase of the electron waves, or their position at a particular point in time-this proved impossible. Gabor theorized that if he could combine the light waves coming off the object with a "coherent reference wave" of the same frequency, the resulting interference pattern would have all the information necessary to construct a 3-D image. Gabor named this interference pattern a "hologram," from the Greek word holos, or "whole," because it would contain complete information about the object.

 

To read the entire article you must log in:

Most of our content — all daily news, blogs, and videos — is free. Magazine stories are paid. To read this story, you must have a subscription or you must use a reading credit. Registration to Technology Review is free and entitles registrants to three free reading credits.

Username or REGISTER
Password  
   
 
Advertisement

MAGAZINE

Can We Build Tomorrow's Breakthroughs?

Manufacturing in the United States is in trouble. That's bad news not just for the country's economy but for the future of innovation.

Sponsored Content

Technologies from National Instruments

Adding Data Logging
Log measured data to a file and open it in Microsoft Excel

> Click here for more National Instruments Videos <
Whitepaper

Temperature Measurements with Thermocouples: How-To Guide

This document is part of the “How-To Guide for Most Common Measurements” centralized resource portal. This tutorial provides a detailed guide for measurement and device considerations to take temperature measurements using thermocouples. Get an introduction to thermocouples, which are inexpensive sensing devices widely used with PC-based data acquisition systems. Also review some specific thermocouple examples and learn how thermocouples work and ways to integrate them into a data acquisition measurement system.

View full PDF > Listen to story >
Find us on Youtube

Videos

Meet 2011 TR35 Winner Jesse Robbins

More

Advertisement

Technology Review Lists

TR50

Our list of the 50 most innovative companies, including the following:

BrightSource Energy

Goldwind Science and Technology

iRobot

Joule Unlimited

More

Advertisement

Facebook

Advertisement