Amplifiers of free-space terahertz radiation

Kao, Tsung -Yu; Reno, John L.; Hu, Qing

doi:10.1364/optica.4.000713

Title: Amplifiers of free-space terahertz radiation

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Abstract

Here, amplifiers of free-space radiation are quite useful, especially in spectral ranges where the radiation is weak and sensitive detectors are hard to come by. A preamplification of the said weak radiation signal will significantly boost the S/N ratio in remote sensing and imaging applications. This is especially true in the terahertz (THz) range where the radiation signal is often weak and sensitive detectors require the cooling of liquid helium. Although quantum cascade structures are promising for providing amplification in the terahertz band from 2 to 5 THz, a THz amplifier has been demonstrated in an integrated form, in which the source is in close proximity to the amplifier, which will not be suitable for the aforementioned applications. Here we demonstrate what we believe is a novel approach to achieve significant amplification of free-space THz radiation using an array of short-cavity, surface-emitting THz quantum cascade lasers operating marginally below the lasing threshold as a Fabry–Perot amplifier. This free-space “slow light” amplifier provides 7.5 dB(×5.6) overall gain at ~3.1 THz. The proposed devices are suitable for low-noise pre-amplifiers in heterodyne detection systems and for THz imaging systems. With the sub-wavelength pixel size of the array, the reflective amplifier can also bemore »« less

Authors:

Kao, Tsung -Yu ^[1]; Reno, John L. ^[2]; Hu, Qing ^[3]

LongWave Photonics LLC, Mountain View, CA (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

Publication Date:: Thu Jul 20 00:00:00 EDT 2017

Research Org.:: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:: 1372355

Report Number(s):: SAND-2017-2577J
Journal ID: ISSN 2334-2536; 651590

Grant/Contract Number:: AC04-94AL85000

Resource Type:: Accepted Manuscript

Journal Name:: Optica

Additional Journal Information:: Journal Volume: 4; Journal Issue: 7; Journal ID: ISSN 2334-2536

Publisher:: Optical Society of America

Country of Publication:: United States

Language:: English

Subject:: 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; semiconductor lasers, quantum cascade; semiconductor lasers; laser amplifiers; optical amplifiers; semiconductor optical amplifiers

Citation Formats


                    Kao, Tsung -Yu, Reno, John L., and Hu, Qing. Amplifiers of free-space terahertz radiation.  United States: N. p., 2017. 
Web.  doi:10.1364/optica.4.000713.

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                    Kao, Tsung -Yu, Reno, John L., & Hu, Qing. Amplifiers of free-space terahertz radiation.  United States.  https://doi.org/10.1364/optica.4.000713

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                    Kao, Tsung -Yu, Reno, John L., and Hu, Qing. Thu .  
"Amplifiers of free-space terahertz radiation".  United States.  https://doi.org/10.1364/optica.4.000713.  https://www.osti.gov/servlets/purl/1372355.

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@article{osti_1372355,

  title        = {Amplifiers of free-space terahertz radiation},

  author       = {Kao, Tsung -Yu and Reno, John L. and Hu, Qing},

  abstractNote = {Here, amplifiers of free-space radiation are quite useful, especially in spectral ranges where the radiation is weak and sensitive detectors are hard to come by. A preamplification of the said weak radiation signal will significantly boost the S/N ratio in remote sensing and imaging applications. This is especially true in the terahertz (THz) range where the radiation signal is often weak and sensitive detectors require the cooling of liquid helium. Although quantum cascade structures are promising for providing amplification in the terahertz band from 2 to 5 THz, a THz amplifier has been demonstrated in an integrated form, in which the source is in close proximity to the amplifier, which will not be suitable for the aforementioned applications. Here we demonstrate what we believe is a novel approach to achieve significant amplification of free-space THz radiation using an array of short-cavity, surface-emitting THz quantum cascade lasers operating marginally below the lasing threshold as a Fabry–Perot amplifier. This free-space “slow light” amplifier provides 7.5 dB(×5.6) overall gain at ~3.1 THz. The proposed devices are suitable for low-noise pre-amplifiers in heterodyne detection systems and for THz imaging systems. With the sub-wavelength pixel size of the array, the reflective amplifier can also be categorized as active metasurface, with the ability to amplify or absorb specific frequency components of the input THz signal.},

  doi          = {10.1364/optica.4.000713},

  journal      = {Optica},

  number       = 7,

  volume       = 4,

  place        = {United States},

  year         = {Thu Jul 20 00:00:00 EDT 2017},

  month        = {Thu Jul 20 00:00:00 EDT 2017}

}

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