Air Laser-based TErahertz SpectroScopy of Explosives (ALTESSE) (Conference Presentation)

Poly(L-lactide) (PLLA) was investigated by Fourier transform terahertz (THz) spectroscopy over the frequency range of 1.0 – 8.5 THz. THz absorption spectra were acquired for PLLA samples isothermally crystallized at...

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Excited state dynamics of conducting polymers studied by time-resolved optical and terahertz spectroscopy

2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) ◽

10.1109/irmmw-thz46771.2020.9370564 ◽

2020 ◽

Author(s):

F. Dutin ◽

J. Degert ◽

M. Tondusson ◽

M. Bousquet ◽

E. Cloutet ◽

...

Keyword(s):

Excited State ◽

Conducting Polymers ◽

Terahertz Spectroscopy ◽

Time Resolved ◽

Excited State Dynamics

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Elemental, Optical, and Time-Domain Terahertz Spectroscopy Studies on Methyl p-Hydroxybenzoate Single Crystal for THz Applications

Journal of Electronic Materials ◽

10.1007/s11664-021-09138-6 ◽

2021 ◽

Author(s):

Debabrata Nayak ◽

N. Vijayan ◽

Manju Kumari ◽

Pargam Vashishtha ◽

Sudha Yadav ◽

...

Keyword(s):

Single Crystal ◽

Time Domain ◽

Terahertz Spectroscopy ◽

Time Domain Terahertz Spectroscopy ◽

Spectroscopy Studies ◽

Thz Applications

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Ultra-Narrow Metallic Nano-Trenches Realized by Wet Etching and Critical Point Drying

Nanomaterials ◽

10.3390/nano11030783 ◽

2021 ◽

Vol 11 (3) ◽

pp. 783

Author(s):

Jeeyoon Jeong ◽

Hyosim Yang ◽

Seondo Park ◽

Yun Daniel Park ◽

Dai-Sik Kim

Keyword(s):

Critical Point ◽

Terahertz Spectroscopy ◽

High Surface ◽

Wet Etching ◽

Drying Process ◽

Metal Structures ◽

Critical Point Drying ◽

Metal Insulator Metal ◽

Gap Width ◽

Optical Structure

A metallic nano-trench is a unique optical structure capable of ultrasensitive detection of molecules, active modulation as well as potential electrochemical applications. Recently, wet-etching the dielectrics of metal–insulator–metal structures has emerged as a reliable method of creating optically active metallic nano-trenches with a gap width of 10 nm or less, opening a new venue for studying the dynamics of nanoconfined molecules. Yet, the high surface tension of water in the process of drying leaves the nano-trenches vulnerable to collapsing, limiting the achievable width to no less than 5 nm. In this work, we overcome the technical limit and realize metallic nano-trenches with widths as small as 1.5 nm. The critical point drying technique significantly alleviates the stress applied to the gap in the drying process, keeping the ultra-narrow gap from collapsing. Terahertz spectroscopy of the trenches clearly reveals the signature of successful wet etching of the dielectrics without apparent damage to the gap. We expect that our work will enable various optical and electrochemical studies at a few-molecules-thick level.

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Terahertz characterization of two-dimensional low-conductive layers enabled by metal gratings

Scientific Reports ◽

10.1038/s41598-021-82560-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Prashanth Gopalan ◽

Yunshan Wang ◽

Berardi Sensale-Rodriguez

Keyword(s):

Optical Transmission ◽

Terahertz Spectroscopy ◽

Design Guidelines ◽

Two Dimensional ◽

Highly Sensitive ◽

Transmission Measurements ◽

Metal Gratings ◽

Low Sensitivity ◽

Non Destructive

AbstractWhile terahertz spectroscopy can provide valuable information regarding the charge transport properties in semiconductors, its application for the characterization of low-conductive two-dimensional layers, i.e., σs < < 1 mS, remains elusive. This is primarily due to the low sensitivity of direct transmission measurements to such small sheet conductivity levels. In this work, we discuss harnessing the extraordinary optical transmission through gratings consisting of metallic stripes to characterize such low-conductive two-dimensional layers. We analyze the geometric tradeoffs in these structures and provide physical insights, ultimately leading to general design guidelines for experiments enabling non-contact, non-destructive, highly sensitive characterization of such layers.

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