Saturday, March 16, 2013

Why terahertz?

The terahertz (THz) portion of the electromagnetic spectrum (0.1 THz to 30 THz) provides unique features for materials characterization (Note: 1 THz = 1000 GHz). THz radiation can penetrate most materials; thus, it can interrogate surfaces, sub-surface, and interior layers of a multilayered material. Unlike X-ray, THz is non-ionizing and does not damage delicate features. It is safe for live imaging on humans. THz radiation is highly sensitive and can detect nanometer-size defects. ARP’s proprietary smart measurement instrument systems can provide precise characterization of wafers, skin, and other substrates. ARP’s THz scanners are non-contact, non-invasive measurement system, with an adjustable stand-off distance.

Applications ARP offers services for application development in areas of customer needs. ARP will install custom manufactured machines in the customer premise. ARP is the industry leader in terahertz (THz) technology. ARP’s proprietary technology offers the world’s widest THz spectral range and highest (CW) power (not pulsed). APR’s scanning, imaging, and time-domain instruments are used in industrial and academia research. ARP can provide a custom-made instrument to address your needs. APR can provide THz R&D services on a contract basis, to fit your needs and budget. APR can help you solve your knotty materials characterization problems.

Products and Services
Terahertz Sub-Surface Nano-Scanner/3D Imager
Semiconductor industry—used for defects detection and identification of causes of wafer rejection. May also be used for wafer polishing (CMP) process control.
Biomedical industry—used for sub-surface imaging of skin, teeth and other tissues. Imaging can be done in-vivo or ex-vivo. This is important for early detection of melanoma, for example.
Other industry—various defects can be identified and quantified: inclusions, cracks, particles , non-uniformity, paint layer thickness, coating thickness, coating penetration, paper thickness, etc.
Terahertz surface tomogram of a substrate
A micro-bubble inside an epoxy disk

Terahertz Time-Domain Spectrometer (TeraSpectra)ARP’s TeraSpectra is used in studies of molecular properties of materials or interactions between two or more materials. TeraSpectra is used in analytical laboratories, pharmaceutical manufacturing, quality control, and more. Spectral characterization is available for specimens in solid, liquid, or gaseous form. TeraSpectra can be configured to accommodate a variety of samples and sizes. TeraSpectra reproduces features found in IR/Raman spectroscopy and identifies features not seen by other techniques. TeraSpectra opens the door to potentially discover new features of materials and new phenomena.

Absorbance spectrum of polyethylene (PE). For samples prepared on a PE card, this spectrum will serve as the background [1].

Terahertz Scanning Reflectometer (TeraScanR)
The TeraScanR is used for non-invasive transdermal characterization (also called thickness profiling). It may be used for characterization of transdermal delivery of drugs, personal care products, and also in quality control. Moreover, this is a general method that is applicable to any substrate and analyte combinations, thus help characterization of just about any substrates. Examples include: Transdermal drug delivery Permeation kinetics of analytes Moisture permeation in substrates Direct quantitation of diffusion kinetics Other substrate-analyte combination. Having a resolution of a few nm, it offers precise profiling of concentration distribution along the thickness of substrate in non-contact fashion.

Depth scan of stratum corneum (SC). Permeation saturation curve (blue) subtracted from reference (red) yields the profile of analyte (hydrocortisone, HC) in the skin (green); more HC penetrates the SC [2].

Terahertz Imaging System (TeraImager)
Terahertz imager can see through boxes and opaque packages. Thus, this technology has applications for scanning packages and envelope for and security. ARP has developed a remote detection system for mobile surveillance (e.g., hidden gun from a patrol vehicle).

For pricing and testimonial please contact:
Anis Rahman, PhD
Applied Research & Photonics, Inc.
470 Friendship Road, Suite 10
Harrisburg PA 17111 USA
Phone: +1-717-623-8201
Fax: +1-717-566-1177
E-mail: info@arphotonics.net
http://arphotonics.net

References
[1]. Proc. SPIE 8261, 82610H (2012); http://dx.doi.org/10.1117/12.902289
[2]. Drug Development & Delivery, May 2012, Vol. 12, No. 4, pp. 43--49.