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New calibration service tunes high-power lasers
The National Institute of
Standards and Technology
(NIST), Gaithersburg, Md.,
launched a new calibration
service for high-power lasers
used by manufacturers for ap-
plications such as cutting and
welding metals, as well as by
the military for more special-
ized applications like defusing
unexploded land mines. The
new service is offered for
power levels up to 10 kW.
NIST recently completed its
first high-power calibration,
for a commercial 5 kW laser power meter. The measurement had an uncertainty of about
1% over two standard deviations, the accuracy and precision threshold necessary for mil-
itary and advanced manufacturing applications.
“That level of uncertainty at multi-kilowatt levels is unprecedented,” says calibration
leader Josh Hadler. Exact laser output must be known to achieve effective, safe perform-
ance in virtually all applications at these power levels. To establish the new service, a 10 kW
fiber laser was purchased and a laboratory was extensively renovated to meet electrical re-
quirements and add appropriate safeguards such as walls with high damage tolerance and
special optics and beam controls for the laser. Running lasers are viewed from behind a
protective barrier, using a multi-camera system for monitoring and control. Laser light is
absorbed by a conventional calorimeter surrounded and cooled by flowing water. The tem-
perature difference between incoming and outgoing water is measured and used to calcu-
late laser power.
The new facility will also be used for research on the fundamental physical processes that
occur during laser welding. The study aims to overcome technical challenges such as weld-
ing of materials that are dissimilar or have different thicknesses. Further, the ability to join dis-
similar materials with vastly different properties could help overcome longstanding design
and cost hurdles associated with welding.
Specialized microscope captures nanotube defects
University of Oregon chemists devised a way to see the internal structures of electronic
waves trapped in carbon nanotubes (CNTs) by external electrostatic charges. CNTs are
touted as exceptional materials with unique properties that allow for extremely efficient
charge and energy transport, with the potential to enable more efficient types of electronic
and photovoltaic devices. However, these traps, or defects, in ultrathin nanotubes can com-
promise their effectiveness. Using a custom-built microscope capable of imaging matter at
the atomic scale, researchers are able to visualize the traps, which can adversely affect the
flow of electrons and elementary energy packets called excitons.
According to physical chemistry professor George V. Nazin, the
study modeled the behavior often observed in carbon nanotube-based
electronic devices, where electronic traps are induced by stochastic ex-
ternal charges in the immediate vicinity of the nanotubes. The exter-
nal charges attract and trap electrons propagating through nanotubes.
“Our visualization should be useful for developing a more accurate pic-
ture of electron propagation through nanotubes in real-world applica-
briefs
NSL Analytical Services Inc.,
Cleveland, an independent
commercial testing laboratory,
received
renewed
accreditation
for ISO/IEC 17025. The
accreditation certificates from
ACLASS, the ILAC-approved
accreditation body for NSL, are
available for download at
A research group led by Kazuhiro
Hono at the National Institute for
Materials Science, Tsukuba,
Japan, synthesized a new
magnetic compound that requires
fewer rare earth elements than the
currently used neodymium iron
boron compound. The ratio of
neodymium, iron, and nitrogen in
the new compound, NdFe12N, is
1:12:1. Its neodymium
concentration is 17% compared to
27% for Nd2Fe14B, the main
component used in the strongest
permanent magnets. Further, the
new compound’s intrinsic hard
magnetic properties were found to
be superior to those of Nd2Fe14B.
Bruker Corp., Fremont, Calif.,
completed
divestiture of its gas
chromatography
(GC) and GC single-quadrupole
(GC-SQ) mass spectrometry
products to Techcomp Europe
Ltd., a subsidiary of Techcomp
(Holdings) Ltd, on October 31.
Techcomp will continue to
manufacture the former Bruker GC
and GC-SQ Scion products in the
Fremont factory previously
occupied by Bruker’s Chemical and
Applied Markets division.
Bruker will continue to
provide service and
support for all GC and
GC-SQ products
worldwide. .
ADVANCED MATERIALS & PROCESSES • NOVEMBER-DECEMBER 2014 8
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NIST’s new calibration service for high-power lasers is
controlled from behind a protective barrier. Paul Williams (left)
and Joshua Hadler operate the service, which can calibrate
lasers with up to 10 kW of power for manufacturers and
military customers. Courtesy of Burrus/NIST.
University of Oregon professor George Nazin uses a scanning tunneling
microscope fitted with a closed-cycle cryostat to uncover traps, or defects,
that disrupt electronic waves in nanotubes.