1,720,986 research outputs found
IMAGING OF FREE CARRIERS IN SEMICONDUCTORS VIA OPTICAL FEEDBACK IN THZ QUANTUM CASCADE LASERS
No full textTo monitor the density of photo-generated charge carriers on a semiconductor surface, we
demonstrate a detectorless imaging system based on the analysis of the optical feedback in
terahertz quantum cascade lasers. Photo-excited free electron carriers are created in high resistivity
n-type silicon wafers via low power (ffi40 mW/cm2) continuous wave pump laser in the near
infrared spectral range. A spatial light modulator allows to directly reconfigure and control the
photo-patterned intensity and the associated free-carrier density distribution. The experimental
results are in good agreement with the numerical simulations
Role of heat accumulation on the incubation effect in multi-shot laser ablation of stainless steel at high repetition rates
No full text
THz imaging of free carrier density based on quantum cascade lasers under optical feedback
No full textWe demonstrate a detectorless THz imaging based on quantum cascade lasers operating under optical feedback to monitor the spatial distribution of free electron plasma induced onto a semiconductor by photo-excitation with a reconfigurable pattern of NIR laser pump
Simultaneous measurement of multiple target displacements by self-mixing interferometry in a single laser diode
No full textWe demonstrate that a single all-optical sensor based on laser diode self-mixing interferometry can monitor the independent displacement of individual portions of a surface. The experimental evidence was achieved using a metallic sample in a translatory motion while partly ablated by a ps-pulsed fiber laser. A model based on the Lang-Kobayashi approach gives an excellent explanation of the experimental results
Direct in-situ measurement of the ablation rate in short pulse laser percussion drilling of metal targets
No full textSimultaneous measurement of multiple target displacements by self-mixing interferometry in a single laser diode
No full text- …
