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Sources and Detectors Group


The Sources and Detectors Group conducts research on the characterization of lasers, detectors, and related components. Principally through measurement services and innovation, the group provides the optoelectronics industry with traceability to national standards. Activities of the group are currently carried out in three project areas: Laser Radiometry, Laser Applications, and Terahertz Imaging and Sources. 

Research in the Laser Radiometry Project is concerned with measuring laser, detector, and component properties such as laser power, laser beam profile, detector spectral responsivity, detector linearity and the attenuation of transmission components. To calibrate detectors and instruments used to measure the power or energy produced by a laser, the project has developed a family of standards that allow the accurate comparison of absorbed optical power to dissipated electrical power. Together, these standards permit calibrations at power levels from nanowatts to hundreds of kilowatts and energy levels from femtojoules to megajoules. Wavelength ranges include the visible through the near infrared, and selected wavelengths in the ultraviolet and mid infrared. For more information, see the Measurement Services section of this site. Instruments designed to receive power either in collimated beams or through optical fibers can be accommodated.

High power lasers capable of continuous output powers ranging from hundreds of watts to tens-of-thousands of watts present exciting opportunities for rapid, directed delivery of energy – particularly in the area of materials processing and laser machining. These same high power lasers also present difficult challenges for the accurate measurement of their delivered power. The Laser Applications Project exists to enhance NIST's ability to measure high power laser output parameters with the necessary accuracy and ease of use. This is done by developing, testing, and implementing unique technologies such as a thermal flowing-water-based approach and a force-based technique using optical radiation pressure. The Laser Applications Project also makes use of NIST's high power laser facilities to develop technologies and measurement tools associated with laser machining and materials processing. Our10 kW fiber laser and integrated laser welding booth provide opportunity for the development of supporting metrology for materials processing related to such applications as photovoltaic manufacturing and laser welding.


Laser Radiometry—Accurate characterization of photonic equipment is important for optical communications, medical devices, semiconductor lithography, manufacturing and materials processing. Our project focuses on …

Terahertz Imaging and Sources—Imaging in the terahertz frequency range enables the detection of concealed weapons and other contraband (e.g., explosives under clothing) without the use of ionizing radiation. Spectroscopy in …

"cupcakes" of vertically aligned carbon nanotube arrays (VANTAs) grown on silicon
"Cupcakes" of vertically aligned carbon nanotube arrays (VANTAs) grown on silicon, which appears blue in the photo. (Photo: Tomlin/NIST)
Illustration of a dual laser frequency comb setup (depicted as rainbow-colored cartoons) to detect the simultaneous signatures of "greenhouse" gases along a 2 km path. (Photo: Burrus and Irvine/NIST)

John Lehman, Group Leader

Mail Stop 815.01
325 Broadway
Boulder, CO 80305-3328

Sources and Detectors Group Staff Directory