TISCH—Terahertz Imaging and Spectroscopy in Cultural Heritage: applications in archaeology, architecture and art conservation science
Returning to our cultural heritage theme, Bianca Jackson tells us about “TISCH—Terahertz Imaging and Spectroscopy in Cultural Heritage: applications in archaeology, architecture and art conservation science”. Terahertz spectroscopy and imaging of Paleolithic cave etchings, 14th century paintings in a church and a mid-20th century Italian painting are all described. This helps demonstrate the versatility of the technique as well as its potential in cultural heritage preservation.
Researchers have nearly doubled the continuous output power of a terahertz quantum cascade laser. Increasing the continuous output power of these lasers is an important step toward increasing the range of practical applications.
Terahertz radiation is of growing interest due to its potential for new spectroscopy and imaging applications as well as wireless communication networks with extremely high bandwidth. However, there are few off-the-shelf components available for manipulating terahertz waves.
TOptica’s new time-domain terahertz platform, TeraFlash, and the CW-terahertz spectrometer, TeraScan, both have a peak dynamic range >90 dB.
Terahertz imaging technology has the potential to help conservationists and academics better understand the history behind cultural artefacts.
A newly devised frequency comb provides a powerful light source, spanning frequencies of over 550 GHz with a total power of 5 mW. At the heart of the frequency combs are terahertz (THz) quantum cascade lasers (QCLs), which have the advantage of having both high power (in the form of THz radiation) and broadband capabilities (since the QCLs have gain over a wider frequency range). Combining these two elements to make a compact frequency comb generating long-wavelength light in the THz range can produce a useful source of radiation for a variety of applications in imaging, diagnostics, remote sensing and spectroscopy of extremely complex molecules.
The use of the terahertz region is in the headlines at present with its ability to screen passengers at airports, but it has important uses in the analytical field as well. This article reviews the latest research on proteins and peptides using THz-TDS, p-germanium lasers (75–85 cm–1) and far-infrared Fourier transform spectroscopy below 350 cm–1.
A compact Terahertz spectroscopy/imaging system with the ability to select between the two on demand. In spectroscopy mode, the instrument can easily be switched between transmittance, reflectance or ATR. In imaging mode, the thickness and/or interface adhesion of coating films of tablets are represented in 1D, 2D or 3D. A process monitoring module will be available soon.
Toptica has presented its compact, frequency-domain terahertz spectrometer. The system combines the company's TeraBeam, a highly integrated two-colour diode laser, with newly developed InGaAs/InP emitter and detector technology from the Fraunhofer Heinrich- Hertz Institute. The new cw THz system features a fast scan option, which reduces the acquisition times and acquires a complete THz spectrum in less than a minute. Making use of integrated DFB laser diodes and fibre components, the laser provides 30 mW per two-colour output and is therefore suited to the power requirements of the cw THz emitters and detectors. The emitter uses a high-bandwidth photodiode with an integrated waveguide structure and provides output levels in the microwatt range. The receiver employs an InGaAs photoconductor and achieves good SNR values up to 80 dB. The modules are fully packaged with SM/PM fibre pigtails.
TeraView has appointed LOT-Oriel as its exclusive agents for Germany, France, Switzerland, Austria and Italy. www.teraview.com
Newport's Spectra-Physics Lasers Division has introduced an expanded portfolio of ultrafast laser products, including two ultrafast amplifers, the 4 W Spitfire Pro XP and the 3.5 W Solstice. The 4 W Spitfire Pro XP regenerative amplifier outputs < 35 fs pulses at 4 W average power at 1 kHz, 5 kHz or 10 kHz. The 3.5 W Solstice one-box amplifier generates 3.5 W average power at 1 kHz, 5 kHz or 10 kHz. The beam quality and pulse intensity make these amplifiers suitable for advanced scientific applications such as time-resolved spectroscopy, terahertz generation, coherence control and high-harmonic generation.Newport Spectra-Physics Issue: 21/01 RSN: 113
Picometrix has received two new terahertz contracts from the US Air Force totalling $850,000 for development of a higher power THz transmitter for surface and gas spectroscopy applications to work with the T-Ray 4000 system, and a Phase I SBIR contract for development of semiconductor material capable of increasing THz power. www.picometrix.com
T-Ray Science has licensed a terahertz detection technology from the Massachusetts Institute of Technology (MIT) which enables detection of continuous wave THz radiation. www.t-rayscience.com
TeraView has conducted successful proof of principal for high-speed measurements of coating thickness on tablets applicable to on-line tablet inspection. The non-contact, non-destructive technique may also be extended to on-line measurement of other key product attributes such as coating or core density tablet delamination and many other parameter's characterising the performance of drugs. This capability opens up the opportunity for deployment of terahertz sensors in non-destructive tablet inspection to ensure that pharmaceutical products remain within the specifications necessary to ensure therapeutic efficacy and drug performance.Teraview LimitedIssue: 20/02 RSN:
TeraView says that its terahertz imaging and spectroscopy products could be employed to help regulatory authorities, law enforcement agencies and industry screen for counterfeit drugs. www.teraview.com
Pittcon 2007 has launched a new, re-designed website. www.pittcon.org
Tags: Atomic absorption Atomic emission ICP-MS Luminescencefluorescence Infrared Near infrared Mass spectrometry Laser spectroscopy NMR ESR EPR Raman Surface analysis UVvis X-ray spectrometry Atomic fluorescence RMs and standards Far infrared Gamma-ray Imaging Ion mobility MRI Mobile Plasma Polarimetry Process Related equipment Sampling Separation science Software Spectroradiometry X-ray diffraction Microscopy Chemometrics Terahertz
Advanced Photonix has announced that its subsidiary, Picometrix, has received orders for its T-Ray 2000 terahertz system from the four major defence and leading university application development labs around the world. The combined orders total slightly over $1million. www.advancedphotonix.com
Toptica has appointed Howard Potter as their direct representative for UK and Ireland. www.toptica.com
Technological advances in terahertz pulsed systems bring far-infrared spectroscopy into the spotlight
Philip F. Taday and David A. NewnhamTeraView Limited, 302/304 Cambridge Science Park, Milton Road, Cambridge, CB4 0WG, UK. E-mail: firstname.lastname@example.org