Maser Focusing Assembly

This object, the focusing assembly from the second maser, was made at Columbia University in 1954 by a team led by physicist Charles H. Townes. Maser stands for Microwave Amplification by Stimulated Emission of Radiation. Masers operate on the same principals as lasers, but they amplify microwaves instead of light. In fact, masers came first. Microwaves have lower energy levels than light and so were easier to produce, although the maser was not a simple invention.
After working on microwave radar and other devices during the Second World War, Townes undertook investigations of microwave spectroscopy at Columbia University. Working with James Gordon and Herbert Zeigler, he successfully demonstrated an ammonia-beam maser in April 1954. The unit was quite large so Townes developed a smaller unit later that year, several pieces of which were donated to the Smithsonian in 1965.
Currently not on view
Object Name
Maser, Part of
maser component
date made
associated date
Townes, Charles H.
Physical Description
ceramic (part material)
brass (part material)
glass (part material)
overall: 10 1/4 in x 10 1/4 in x 4 1/2 in; 26.035 cm x 26.035 cm x 11.43 cm
ID Number
catalog number
accession number
Energy & Power
Science & Mathematics
See more items in
Work and Industry: Electricity
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
from Charles H. Townes and Columbia University
Additional Media

Visitor Comments

Add a comment about this object

**Please read before submitting the form**

Have a comment or question about this object to share with the community? Please use the form below. Selected comments will appear on this page and may receive a museum response (but we can't promise). Please note that we generally cannot answer questions about the history, rarity, or value of your personal artifacts.

Have a question about anything else, or would you prefer a personal response? Please visit our FAQ or contact page.

Personal information will not be shared or result in unsolicited e-mail. See our privacy policy.

Enter the characters shown in the image.