D. Chamberlin | UC Berkeley (original) (raw)

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Research paper thumbnail of <title>Optimization of a 3.6-THz quantum cascade laser for real-time imaging with a microbolometer focal plane array</title>

Terahertz Technology and Applications, 2008

Real-time imaging in the terahertz (THz) spectral range was achieved using a 3.6-THz quantum casc... more Real-time imaging in the terahertz (THz) spectral range was achieved using a 3.6-THz quantum cascade laser (QCL) and an uncooled, 160×120 pixel microbolometer camera fitted with a picarin lens. Noise equivalent temperature difference of the camera in the 1-5 THz frequency range was calculated to be at least 3 K, confirming the need for external THz illumination when imaging in this frequency regime. After evaluating the effects of various operating parameters on laser performance, the QCL found to perform optimally at 1.9 A in pulsed mode with a 300 kHz repetition rate and 10-20% duty cycle; average output power was approximately 1 mW. Under this scheme, a series of metallic objects were imaged while wrapped in various obscurants. Single-frame and extended video recordings demonstrate strong contrast between metallic materials and those of plastic, cloth, and paper - supporting the viability of this imaging technology in security screening applications. Thermal effects arising from Joule heating of the laser were found to be the dominant issue affecting output power and image quality; these effects were mitigated by limiting laser pulse widths to 670 ns and operating the system under closed-cycle refrigeration at a temperature of 10 K.

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Research paper thumbnail of Use of 2.7-THz quantum cascade laser and microbolometer camera for imaging of concealed objects

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Research paper thumbnail of High intensity 1.3-1.6μm luminescence from MBE grown GaInNAsSb

International Conference on Molecular Bean Epitaxy, 2002

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Research paper thumbnail of Failure mode analysis of oxide VCSELs in high humidity and high temperature

Journal of Lightwave Technology, 2003

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Research paper thumbnail of High-Quality Single-Walled Carbon Nanotubes with Small Diameter, Controlled Density, and Ordered Locations Using a Polyferrocenylsilane Block Copolymer Catalyst Precursor

Chemistry of Materials, 2005

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Research paper thumbnail of Nanoparticle measurement by Spectroscopic Mie Scattering

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Research paper thumbnail of <title>Optimization of a 3.6-THz quantum cascade laser for real-time imaging with a microbolometer focal plane array</title>

Terahertz Technology and Applications, 2008

Real-time imaging in the terahertz (THz) spectral range was achieved using a 3.6-THz quantum casc... more Real-time imaging in the terahertz (THz) spectral range was achieved using a 3.6-THz quantum cascade laser (QCL) and an uncooled, 160×120 pixel microbolometer camera fitted with a picarin lens. Noise equivalent temperature difference of the camera in the 1-5 THz frequency range was calculated to be at least 3 K, confirming the need for external THz illumination when imaging in this frequency regime. After evaluating the effects of various operating parameters on laser performance, the QCL found to perform optimally at 1.9 A in pulsed mode with a 300 kHz repetition rate and 10-20% duty cycle; average output power was approximately 1 mW. Under this scheme, a series of metallic objects were imaged while wrapped in various obscurants. Single-frame and extended video recordings demonstrate strong contrast between metallic materials and those of plastic, cloth, and paper - supporting the viability of this imaging technology in security screening applications. Thermal effects arising from Joule heating of the laser were found to be the dominant issue affecting output power and image quality; these effects were mitigated by limiting laser pulse widths to 670 ns and operating the system under closed-cycle refrigeration at a temperature of 10 K.

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Research paper thumbnail of Use of 2.7-THz quantum cascade laser and microbolometer camera for imaging of concealed objects

Bookmarks Related papers MentionsView impact

Research paper thumbnail of High intensity 1.3-1.6μm luminescence from MBE grown GaInNAsSb

International Conference on Molecular Bean Epitaxy, 2002

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Failure mode analysis of oxide VCSELs in high humidity and high temperature

Journal of Lightwave Technology, 2003

Bookmarks Related papers MentionsView impact

Research paper thumbnail of High-Quality Single-Walled Carbon Nanotubes with Small Diameter, Controlled Density, and Ordered Locations Using a Polyferrocenylsilane Block Copolymer Catalyst Precursor

Chemistry of Materials, 2005

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Research paper thumbnail of Nanoparticle measurement by Spectroscopic Mie Scattering

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