Physics Photo of the Week
October
9, 2009
CCD Dectors - 2009 Nobel Prize in Physics
Astronomy,
medical imaging, and ordinary photography have been revolutionized by
the development of solid state imaging detectors called CCD
arrays. These devices were invented and developed in the late
1960's by Willard Boyle and George Smith at Bell Labs in the USA.
The proven technology in the past 40 years has earned Boyle and Smith
half the 2009 Nobel Prize in Physics announced earlier this week.
This photo shows a CCD detector (Charged Coupled Device) as part of an
astronomical camera. A highly magnified view of the detector is
shown in the lower picture where we can barely see the indivual pixels
of the detector. Each tiny pixel is approximately 10 microns
(0.01 mm) across.
CCD
detectors have made the development of consumer digital cameras
entirely possible. They are also found in virtually all video
cameras - even the cameras used for broadcast TV. Of course all
the photos featured in Physics Photo of the Week are taken with digital
cameras fitted with these solid state arrays. Digital photos
naturally promote the use of photos through computer technology.
The main technological advantage to solid-state digital photography -
besides compactness, low power consumption, non-expendable film,
instant "developing" - are that the output signals are proportional to
the amount of light striking the detector. Traditional film is
highly non-linear. The linear output makes these detectors
excellent where the light intensity needs to be measured.
Astronomy was the first discipline to widely adopt the use of these
detectors for this reason. Recent graduates Hannah Barks (2006)
and George Keel (2008) used the camera featured here to perform
excellent photometry on stars for their Natural Science Seminar
projects.
CCD detectors consist of 2-dimensional arrays of phototransistors on a
single chip of silicon called an Integrated Circuit. (See PPOW
for December 8, 2006 and November
18, 2005. The Swedish Academy had previously recognized
transistors and integrated circuits for their significant
contribution to technology: The discovery of the transistor in
1948 by John Bardeen, Walter Brattain, and William Shockley earned them
the 1956 Nobel Prize in Physics. The development of integrated
circuits - many transistors on a single chip of silicon - in the early
1960's by Jack St. Clair Killay - earned a portion of the 2000 Nobel
Prize in Physics.
Besides recognizing the ubiquitous technology responsible for digital
imaging, the Nobel Committee awarded the other half of the 2009 Nobel
Prize in physics to Charles Kao for the development of special optical
fibers for communication. Although we don't ordinarily see the
optical fibers, they are responsible for the vast increase in internet
speed as well as lower costs for long distance communication.
Thank yous are extended to Natasha Shipman of the Biology Department
for lending a dissecting microscope through which the
microscopic image of the chip using was photographed using a digital
camera.
Physics
Photo of the
Week is
published weekly during the academic year on Fridays by the Warren
Wilson College Physics
Department. These photos feature interesting phenomena in
the world around us. Students, faculty, and others are invited to
submit digital (or film) photographs for publication and
explanation. Atmospheric phenomena are especially welcome.
Please send any photos to dcollins@warren-wilson.edu.
All photos and discussions are copyright by Donald
Collins or by the person credited for the photo and/or
discussion. These photos and discussions may be used for private
individual use or educational use. Any commercial use without
written permission of the photoprovider is forbidden.
Click
here to see the Physics Photo
of
the Week Archive.
Observers are invited to submit
digital photos to:
