Tuesday 30 June 2015

Quad-band THz frequency selective surface based on a split ring resonator loaded with multiple slots

Abstract

A quad-band terahertz (THz) frequency selective surface with bandstop response is designed, fabricated, and characterized. The unit cell of the filter consists of a split ring resonator (SRR) and surrounding four groups of slots. Each group of slots has three slots with different lengths. The lowest frequency band is determined by the resonance of the SRR and the other three upper bands are selected by the resonance of the slots which exhibit bandstop characteristics rather than bandpass characteristics. The filter transformation characteristic originates from the slits placed between the unit cells which act as series-connected capacitive components. The fabricated quad-band THz filters exhibited bandstop characteristics with attenuation higher than 20 dB in all the operating frequency bands.
The quad-band FSSs were characterized using TeraView's time domain spectroscopy system - the TPS Spectra 3000.
http://www.tandfonline.com/doi/abs/10.1080/09205071.2015.1053576

Thursday 25 June 2015

Laser 2015: terahertz technologies - a growing market

Laser 2015: terahertz technologies - a growing market

Properties of two-component nematic liquid crystal mixtures in the range of 0.3–3.0 THz

TeraView's TPS Spectra 3000 was used to investigate nematic liquid crystals in the range of 0.3–3.0 THz.


http://www.tandfonline.com/doi/abs/10.1080/02678292.2015.1036816#.VYvdFvlViko


Abstract

In this work, we present the results of terahertz measurements of five nematic liquid crystal materials. Optical properties like refractive indices, birefringence and absorption coefficients of liquid crystals (LCs) for ordinary and extraordinary polarisation were compared. The aim of this study was to check the impact of the structure of LC molecules on above properties. The compounds with different core structure and various number of laterally substituted fluorine atoms were chosen. A standard terahertz Time-Domain Spectrometer to measurements from 0.3 THz to 3 THz was used.


Wednesday 24 June 2015

Thesis - Growth of breast tumors in vitro to characterize a terahertz imaging platform

Biological Sciences 
J. William Fulbright 
College of Arts and Sciences 
The University of Arkansas

Samples analysed in this thesis were imaged
using the TPS Spectra 3000 Teraview and analyzed using the TVL Imaging Suite.

http://dpoc.uark.edu:8080/jspui/bitstream/10826/1187/1/ACKLIN-THESIS-2015.pdf

Tuesday 23 June 2015

TeraView TPS 3000 unit for time domain spectroscopy was used to investigate spectral properties of nematic liquid crystal mixtures

Article

Spectral Properties of Nematic Liquid Crystal Mixtures Composed with Long and Short Molecules in THz Frequency Range


ABSTRACT In this paper the influence of short and long molecules added to liquid crystal
6CHBT were investigated. Change of refractive indices and absorption coefficients
for 6CHBT mixtures were compared in the 0.3 - 3 THz frequency range. Influence of
temperature on the mentioned parameters of liquid crystal were investigated. Our study
show that even a slight change in shape and the composition of the molecules dopants
affects the macroscopic properties of liquid crystal. These properties depend on the
length of chains, the number of benzene or cyclohexane rings or the spatial distribution
of molecules and the interactions between them in the liquid crystal mixture. Spectra
measurements on the terahertz time-domain spectrometer were performed.
Spectral Properties of Nematic Liquid Crystal Mixtures Composed with Long and Short Molecules in THz Frequency Range (PDF Download Available). Available from: http://www.researchgate.net/publication/235218799_Spectral_Properties_of_Nematic_Liquid_Crystal_Mixtures_Composed_with_Long_and_Short_Molecules_in_THz_Frequency_Range [accessed Jun 23, 2015].

Thursday 11 June 2015

TeraView at IRMMW-THz 2015

TeraView invites you to visit us at IRMMW-THz 2015!


"Since 2000, the IRMMW-THz conference series has alternated between Asia, Europe and America on a continuous three year cycle. In 2015, the conference returns to the Asian leg, and will be held in Hong Kong for the first time from August 23 to 28 at the Chinese University of Hong Kong."


TeraView's CEO, Dr. Don Arnone will be in attendance for the event and will be one of the plenary speakers.


TeraView's Dr. Philip Taday will also be attending the event, and will be demonstrating TeraView's flagship instrument, the TeraPulse 4000 in our booth over.


If you would like to pre-arrange a meeting, or a chance to view a demonstration of the TeraPulse 4000, please e-mail Dr. Phil Taday at philip.taday@teraview.com.

Wednesday 10 June 2015

Impact of Processing Conditions on Inter-tablet Coating Thickness Variations Measured by Terahertz In-Line Sensing

HUNGYEN LIN, ROBERT K. MAY, MICHAEL J. EVANS, SHUNCONG ZHONG, LYNN F. GLADDEN, YAOCHUN SHEN,
J. AXEL ZEITLER


Abstract


A novel in-line technique utilising pulsed terahertz radiation for directmeasurement of the film coating thickness of individual tablets during the coating process was previously developed and demonstrated on a production-scale coater. Here, we use this technique to monitor the evolution of tablet film coating thickness and its inter-tablet variability during the coating process under a number of different
process conditions that have been purposefully induced in the production-scale coating process. The changes that were introduced to the coating process include removing the baffles from the coater, adding uncoated tablets to the running process, halting the drum, blockage of spray guns and changes to the spray rate. The terahertz sensor was able to pick up the resulting changes in average coating thickness in the coating drum and we report the impact of these process changes on the resulting coating quality. C⃝ 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci



This study was performed using TeraView's Spectra 3000 system. (TeraView, Cambridge, UK)

Monday 8 June 2015

Photonics West - Call for Papers

This conference brings together researchers and engineers from academia, industry, and government laboratories to explore and present work in the frequency range covering approximately less than 1 GHz (300 mm) to greater than 3 THz (100 μm). Papers on RF and millimeter technology including advances in wireless communications, radar, lidar, microwave and mm-wave photonics, metamaterials, antennas, phased array radar, modulation, security, monitoring, detection, imaging are encouraged. Papers in photonic-related fields including, but not limited to, radio over fiber (RoF) RF photonics including photonic generation of microwave signals, photonic processing of microwave signals, and photonic distribution of microwave signals and semiconductor (including Si, SiC, SOI, GaAs, GaN, InP, SiGe, diamond, graphene and other materials) RF, mm-wave and terahertz devices and related applications are also encouraged, as well as the hybrid photonic systems and applications. Terahertz (THz) technology deals with the generation and utilization of electromagnetic energy covering what is also known as the sub-millimeter wave region of the spectrum. In this region, which lies between the millimeter wave and far infrared spectral regions, materials exhibit properties that can be exploited to advantage for use over a broad range of important technologies and applications. Papers on terahertz photonics including photonic generation and detection of terahertz waves, THz lasers are also encouraged.

Abstracts are due on the 3rd of August 2015, and papers are solicited in the following areas: 

  • Terahertz sources
  • RF, sub-millimeter-wave and millimeter-wave sources
  • Detectors
  • High-power sources, modules, and systems
  • Terahertz, RF, millimeter-wave, and sub-millimeter-wave passive components
  • Materials for THz and GHz devices
  • Enhancements, improvements and advances in RF, millimeter-wave and sub-millimeter wave generation, modulation and detection
  • Simulations and modeling
  • Spectroscopy
  • Biomedical applications
  • Communication and sensing systems
  • Imaging and security
  • Astronomy and space and other areas of photonics, light, and matter
  • Innovations
  • Power supplies and electronic power conditioners
  • Organic electronics

For more information please visit http://spie.org/PWO/conferencedetails/thz-rf-mm-submm-wave-technology

Monday 1 June 2015

An Effective Method for Substance Detection Using the Broad Spectrum THz Signal with a “Terahertz Nose”

Vyacheslav A. Trofimov  and Svetlana A. Varentsova 



Abstract

We propose an effective method for the detection and identification of dangerous substances by using the broadband THz pulse. This pulse excites, for example, many vibrational or rotational energy levels of molecules simultaneously. By analyzing the time-dependent spectrum of the THz pulse transmitted through or reflected from a substance, we follow the average response spectrum dynamics. Comparing the absorption and emission spectrum dynamics of a substance under analysis with the corresponding data for a standard substance, one can detect and identify the substance under real conditions taking into account the influence of packing material, water vapor and substance surface. For quality assessment of the standard substance detection in the signal under analysis, we propose time-dependent integral correlation criteria. Restrictions of usually used detection and identification methods, based on a comparison between the absorption frequencies of a substance under analysis and a standard substance, are demonstrated using a physical experiment with paper napkins.