Emilio Segrè Visual Archives

More than 30,000 photos of scientists and their work

Attention ESVA Patrons:

The Emilio Segrè Visual Archives’ site is moving soon and adopting an open access approach to digital image sharing. Once we have transitioned to the new site in 2021, we will no longer charge for our high-resolution digital images or usage fees (note that we do not hold copyright to all the images in our collections and you will still need to obtain permission for those which we do not own).

If you are working on a long-term project, we advise you to wait until the migration is complete so that you may obtain our copies for free. If you cannot wait, email us at nbl [at] aip.org and we will do what we can to assist you. We will not be offering refunds for past purchases.

For more information, please visit our FAQ page on the Ex Libris Universum blog. 

Hall Robert Noel F1

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Hall Robert Noel F1

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We charge a usage fee per photo if the photo is published, reproduced in a product or publicly exhibited. This is not a license in the legal sense. As a non-profit institution, we do not make any money providing these photographs. It is only by assessing usage fees that we are able to cover the cost of providing publication quality copies of our photos, preserving the photograph collection according to archival standards, and providing access to the collection by maintaining an online image database. The copyright holder may charge a fee in addition to our service fee.

Images are for use in educational projects only and must be used in a respectful manner.

Image title: 
Semiconductor Injection Diode Laser
Credit line: 
General Electric Research and Development Center, courtesy AIP Emilio Segrè Visual Archives

Early Semiconductor Injection Diode Laser - newest laser is a tiny semiconductor crystal shown here suspended inside a glass container filled with liquid nitrogen, which helps keep the device cool when large amounts of electric current are passed through a junction in the crystal to generate a beam of coherent infrared light. Preparing the revolutionary type of laser for operation is Dr. Hall of General Electric Research and Development Center, discoverer of what has been described as 'the simplest, most compact, most efficient, and most direct method yet discovered for producing laser action.' In the reflecting prism below the glass container, the laser crystal can be seen as a small spot between to connecting electrodes.

Photo date: 
Original format: 
1 photographic print (black and white; 8 x 10 inches)
Hall, Robert Noel,1919-