NASA STTR 2009 Solicitation


PROPOSAL NUMBER: 09-2 T7.01-9887
RESEARCH SUBTOPIC TITLE: One-Sided 3D Imaging of Non-Uniformities in Non-Metallic Space Flight Materials
PROPOSAL TITLE: Terahertz Quantum Cascade Laser Based 3D Imaging

NAME: LongWave Photonics, LLC NAME: Massachusetts Institute of Technology
STREET: 15 Bartlett St #3 STREET: 77 Massachusetts Avenue
CITY: Boston CITY: Cambridge
STATE/ZIP: MA  02129 - 2520 STATE/ZIP: MA  02139 - 4301
PHONE: (310) 845-6276 PHONE: (617) 258-8017

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Alan Lee
15 Bartlett St #3
Boston, MA 02129 - 2520
(310) 845-6276

Estimated Technology Readiness Level (TRL) at beginning and end of contract:
Begin: 3
End: 5

TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
LongWave Photonics proposes a terahertz quantum-cascade laser based swept-source optical coherence tomography (THz SS-OCT) system for single-sided, 3D, nondestructive evaluation (NDE) of non-conductive materials. The THz SS-OCT system uses a frequency tunable QCL array to generate an interferometric signal between a reference mirror, and a sample. An algorithm is used to transform this signal into depth information of the interfaces within the sample. Phase I demonstrated the feasibility of measuring the interfaces of a dielectric on metal sample. In Phase II, we propose to demonstrate a complete scanning system for 3D imaging by upgrading the optics and mechanics. Improvements in the power levels and frequency bandwidth of the QCL source are expected to greatly improve the depth resolution and signal to noise ratio of the system. The milliwatt power levels of the QCL are expected to result in fast scan speeds. Operation of the SS-OCT system is expected to be relatively simple as the QCL is an electrically pumped, solid state source of terahertz radiation, capable of operation in a compact, high reliability crycooler as demonstrated in Phase I.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
The proposed THz SS-OCT system will be useful for characterizing the voids and delaminations in materials used in space flight (e.g. urethane based foams, silica based materials, composites, etc). The high depth resolution enabled by this system will also allow measurement of thin non-conductive polymer layers, such as paints and compositions to verify thicknesses and integrity. Further application include inspection for corrosion damage under paint layers or foams.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
Pharmaceutical applications for this technology include in-process monitoring of thicknesses of polymer coatings in controlled
release tablets. Numerous defects in the thin coatings can occur during processing affecting the performance of the tablet, leading
drug complications and drug recalls. The use of QCL based 3D imaging technology could improve the uniformity in a batch tablet
coating process. In the automotive and aerospace industry spray application of paint is both inefficient and environmentally
unfriendly. In situ monitoring of sprayed paint thicknesses would allow reduced paint usage and reduced emissions of volatile organic
compounds (VOCs).

TECHNOLOGY TAXONOMY MAPPING (NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.)
Launch and Flight Vehicle
Optical & Photonic Materials
Portable Data Acquisition or Analysis Tools
Semi-Conductors/Solid State Device Materials
Testing Facilities

Form Generated on 02-01-11 15:25