Evaluation of Terahertz Quantum Cascade Laser Sources as a Potential Portable Non-Destructive Evaluation Method for the Inspection of Aircraft Structures
Final rept. 15 Sep 2008-15 Sep 2009
CAMBRIDGE UNIV (UNITED KINGDOM) CAVENDISH LAB
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This report results from a contract tasking University of Cambridge as follows Description of Work The first phase of the project aims to reproduce the performance figures from the reference THz QCL design. To achieve high temperature operation the device utilises a double-metal DM waveguide. This utilises a novel gold-to-gold thermal compression wafer bonding technique that has been developed at the Cavendish Laboratory which incorporates a self-aligned dry etch process. Standard electrical I-V and lasing emission L-I, L-f, L-T, electroluminescence characterisation will be taken and compared with the simulation data. Following validation of the USAF modelling code the first LO phonon injection design will be fabricated. The design aims to directly inject electrons into the upper state of the lasing transition through an LO phonon transition with the aim of preserving the upper state lifetime at elevated temperatures. Again standard characterisation of this device in a DM waveguide will be performed. Depending on the promise of this design philosophy, further iterative improvements will be scheduled. If the above device shows significantly degraded performance an alternative design approach will be adopted.
- Lasers and Masers
- Nuclear Physics and Elementary Particle Physics
- Quantum Theory and Relativity