Since the first demonstration of electroluminescence (EL) from a CNTFET about three year ago, significant progress
has been achieved in CNT optoelectronics. We have developed semiclassical and quantum transport simulators for
CNT optoelectronic devices. A self-consistent simulation, which couples a quantum treatment of the metal-CNT
contacts to a semiclassical treatment of the channel, is performed to understand carrier transport and light emission in a
CNT infrared emitter. The results show that when the channel is long, light emission significantly affects carrier
transport, and reduces the source-drain current by a factor of 2 in ambipolar transport regime. The experimentally
observed light-spot movement along the channel can be mostly understood and explained by a simple, semiclassical
picture. The photoconductivity of carbon nanotube (CNT) Schottky barrier transistors is studied by solving the nonequilibrium
Green's function transport equation. The model provides a detailed and coherent picture of electron-photon
coupling and quantum transport effects. The photocurrent shows peaks at photon energies near the subband gaps, which
can be engineered by controlling the CNT diameter. Electron-phonon coupling (i) slightly broadens the peaks, (ii) leads
to phonon-assisted photocurrent at certain energy ranges, and (iii) changes the energy-resolved photocurrent. We also
show that the metal/CNT barrier height has a much smaller effect on the photocurrent than on the dark current. We also
show the important role of sub-bandgap impact ionization and excitation in CNT devices.
An approach has been developed for real-time vibration monitoring of a composite cantilever beam. The fiber Bragg grating (FBG) sensor has an advantage to be embedded or bonded to the structure compared with other sensors such as piezoelectric sensor or strain gage, thus allowing the measurement of parameters like strain and temperature. In this paper the vibration sensor system with a FBG embedded in a composite smart structure is proposed. This system can assort vibration direction and sensing vibration amplitude just by measuring output voltage. The sensing resolution is decided by the slope of the filter used in the system.