Impact of substrate characteristics on performance of large area plasmonic photoconductive emitters

Yardimci, Nezih Tolga; Salas, Rodolfo; Krivoy, E. M.; Nair, Hari P.; Bank, Seth R.; Jarrahi, Mona

doi:10.1364/oe.23.032035

Cited by 43 publications

(12 citation statements)

References 35 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…11,12 Suitable photoconductive materials for photomixing must exhibit high dark resistivities, high carrier mobilities, and short carrier lifetimes. 13 Early and current photomixer work focused primarily on low-temperature-grown (LTG) GaAs 14 or superlattices of epitaxially-embedded self-assembled nanoparticles of ErAs [15][16][17] and LuAs [18][19][20] in GaAs. Development of fast photoconductive materials with smaller bandgaps, such as In 0.53 Ga 0.47 As, would benefit greatly from the mature telecommunication component infrastructure available at 1550 nm.…”

mentioning

confidence: 99%

Growth and properties of rare-earth arsenide InGaAs nanocomposites for terahertz generation

Salas

Guchhait

Sifferman

et al. 2015

Applied Physics Letters

View full text Add to dashboard Cite

We explore the effects of surfactant-mediated epitaxy on the structural, electrical, and optical properties of fast metal-semiconductor superlattice photoconductors. Specifically, application of a bismuth flux during growth was found to significantly improve the properties of superlattices of LuAs nanoparticles embedded in In 0.53 Ga 0.47 As. These improvements are attributed to the enhanced structural quality of the overgrown InGaAs over the LuAs nanoparticles. The use of bismuth enabled a 30% increase in the number of monolayers of LuAs that could be deposited before the InGaAs overgrowth degraded. Dark resistivity increased by up to $15Â while carrier mobility remained over 2300 cm 2 /V-s and carrier lifetimes were reduced by >2Â at comparable levels of LuAs deposition. These findings demonstrate that surfactant-mediated epitaxy is a promising approach to enhance the properties of ultrafast photoconductors for terahert generation.

show abstract

mentioning

confidence: 99%

Growth and properties of rare-earth arsenide InGaAs nanocomposites for terahertz generation

Salas

Guchhait

Sifferman

et al. 2015

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…To demonstrate the superior performance of the presented terahertz source, a plasmonic terahertz nanoantenna array is fabricated on a low-temperature-grown GaAs (LT-GaAs) substrate with a carrier lifetime of 0.3 ps 26 . The same device area, the same ratio between the active and shadowed areas, and the same nanoantenna length are chosen for this device to ensure a fair comparison.…”

Section: Resultsmentioning

confidence: 99%

A High-Power Broadband Terahertz Source Enabled by Three-Dimensional Light Confinement in a Plasmonic Nanocavity

Yardimci

Çakmakyapan

Hemmati

et al. 2017

Sci Rep

Self Cite

View full text Add to dashboard Cite

The scope and potential uses of time-domain terahertz imaging and spectroscopy are mainly limited by the low optical-to-terahertz conversion efficiency of photoconductive terahertz sources. State-of-the-art photoconductive sources utilize short-carrier-lifetime semiconductors to recombine carriers that cannot contribute to efficient terahertz generation and cause additional thermal dissipation. Here, we present a novel photoconductive terahertz source that offers a significantly higher efficiency compared with terahertz sources fabricated on short-carrier-lifetime substrates. The key innovative feature of this source is the tight three-dimensional confinement of the optical pump beam around the terahertz nanoantennas that are used as radiating elements. This is achieved by means of a nanocavity formed by plasmonic structures and a distributed Bragg reflector. Consequently, almost all of the photo-generated carriers can be routed to the terahertz nanoantennas within a sub-picosecond time-scale. This results in a very strong, ultrafast current that drives the nanoantennas to produce broadband terahertz radiation. We experimentally demonstrate that this terahertz source can generate 4 mW pulsed terahertz radiation under an optical pump power of 720 mW over the 0.1–4 THz frequency range. This is the highest reported power level for terahertz radiation from a photoconductive terahertz source, representing more than an order of magnitude of enhancement in the optical-to-terahertz conversion efficiency compared with state-of-the-art photoconductive terahertz sources fabricated on short-carrier-lifetime substrates.

show abstract

“…[170][171][172][173] A radiation power of 3.8 mW over the 0.1-to 5-THz range of frequency was demonstrated through this architecture. 174 As of 2017, the best signal to noise ratio achieved for THz TDS using this architecture was reported to be 107 dB over the 0.1-to 4-THz range of frequency. 175 In 2019, a multinational research consortium from the United States, Russia, and Japan reported that current-voltage measurements under femtosecond laser illumination show an increase of the transient photocurrent of 15 times higher than that of conventional photoconductive antennas.…”

Section: Novel Terahertz Photoconductive Antennas With Higher Photon mentioning

confidence: 93%

Survey of terahertz photonics and biophotonics

et al. 2020

View full text Add to dashboard Cite

We review the advances of terahertz (THz) science and technology in biophotonics, including related challenges and solutions. The main impediment to THz spectroscopy and imaging in this field is the high absorption of the THz beam in water. Hence, transmission imaging and spectroscopy of thick wet tissue using THz radiation has generally been quite difficult. However, the absorption of THz waves by water molecules is so strong that increasing the power of the THz source can lead to structural and functional changes in tissues, so solutions must go beyond a larger power output. In terms of resolution, THz imaging is superior to ultrasound but inferior to visible light microscopy. Owing to its unique material analysis capabilities, promising diagnosis applications have been demonstrated through THz imaging and spectroscopy. Unfortunately, many applications are limited by beam penetration depth and resolution. Hence, researchers from a wide variety of scientific and technical fields have been actively improving these features through the development of electronic devices and materials. In addition, groundbreaking optical architecture and materials to reduce beam absorption in the optics of a system and generate focused beams with smaller diameters have been proposed. On the software side, image processing techniques to computationally enhance the resolution and quality of THz imaging have been proposed. Data science and machine learning to automate the diagnosis of defects and diseases through processing THz images and spectroscopy data have been proposed. We have reviewed the applications of THz radiation in biophotonics and research achievements toward advancing these applications. A conclusion with a roadmap toward increasing the footprint of the THz technology in biophotonics is also proposed.

show abstract

Impact of substrate characteristics on performance of large area plasmonic photoconductive emitters

Cited by 43 publications

References 35 publications

Growth and properties of rare-earth arsenide InGaAs nanocomposites for terahertz generation

Growth and properties of rare-earth arsenide InGaAs nanocomposites for terahertz generation

A High-Power Broadband Terahertz Source Enabled by Three-Dimensional Light Confinement in a Plasmonic Nanocavity

Survey of terahertz photonics and biophotonics

Contact Info

Product

Resources

About