Barney DeLoach (left), Richard Dixon
and Robert Hartman at the ceremony
for the 1993 IEEE Gold Medal for
Courtesy of R. W. Dixon
long repeaterless spans (approaching 10,000 km) now often
have the high-performance lasers that encode digital information only at the land ends.
Much simpler continuously operating lasers, which carry
no signal information, are used to pump fiber amplifiers that
are periodically spaced under the sea. Data rates in a single
fiber, using very-high-speed modulation and wavelength divi-
sion multiplexing, in high-volume applications, can approach
1 Tb/s— 20,000 times higher that our initial 45 Mb/s rates!
Our program also supported what was then called “fiber-
to-the-home,” or colloquially “the last mile.” This application
took longer to become a reality because of the breakup of the
Bell System and the high costs of serving individual customers.
I was pleased, and a little nostalgic, when about five years ago
Verizon brought their laser-based FIOS product to my home.
On the consumer products side, I, at least,
did not anticipate the fast and widespread
application of lasers in products such as printers
and CD/DVD players—or the dramatic price
reductions made possible by these high-volume
applications. Both the programs I worked on
and their subsequent applications, through the
efforts of thousands of scientists and engineers
throughout the world, have succeeded beyond
my wildest dreams. t
condensed-matter physics as “Schmutzphysik.”
Did he mean simply that it was complex
and therefore hard? Did he mean that it was
difficult literally because impurities (dirt)
at unheard-of small concentrations affect
everything? Or did he simply mean that any
elegant physics involved was hidden in an
opaque matrix of mud? I sometimes thought
of ourselves as the “mudders.” Fortunately, we
ended up finding gold.
Bob Rediker, a professor at MIT and MIT
Lincoln Labs, expressed his view of our work
I was pleased,
and a little
about five years
to my home.
“In the 1980s and early 1990s, I mounted
a campaign with others to insist that those
who by much hard work made inventions
practical be honored. In particular, I wanted recog-
nition for the team at Bell Telephone Laboratory.
They had increased the mean-time-to-failure at room
temperature of the double-heterostructure Ga As-
based laser … from several minutes in 1970 to an
extrapolated 8 million hours in 1978. [For this work]
B. C. DeLoach, R. W. Dixon, and R. L. Hartman
were awarded the IEEE [Gold] Medal for Engineer-
ing Excellence in 1993.”
I would like to express my gratitude to each one of the
scores of professional scientists, technologists and many
others who contributed to the success of the Bell Labs
semiconductor laser development program during the
last decades of the 20th century. It was fun being along
for the ride.
Richard Dixon ( firstname.lastname@example.org) is a retired Bell Labs Technical Director, Murray Hill, N.J., U.S.A. He currently lives in Bernardsville, N.J., U.S.A.
Semiconductor lasers, then to now
Our efforts in the 1970s, 80s and 90s were aimed at Bell
System applications in long-distance, high-volume voice, data
and video transmission—both on land and undersea. Today,
essentially all terrestrial and undersea telecommunications,
data and television traffic above the local distribution level is
carried in fiber using lasers as sources. The Internet would not
be possible without these laser devices. Undersea cables with
ONLINE EX TRA: Visit www.osa-opn.org for a complete
list of references and resources related to this article.
[ References and Resources ]
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>> B.C. DeLoach Jr. et al. “Degradation of CW GaAs double-hetero-junction lasers at 300K,” Proc. IEEE 61, 1042 (1973).
>> P. Petroff and R. L. Hartman. “Defect structure introduced during
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48 | OPN Optics & Photonics News