Gabriel Lombardi - Academia.edu (original) (raw)
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Papers by Gabriel Lombardi
The Astrophysical Journal, 1987
The Astrophysical Journal, 1981
A coherent lidar was used to detect sound remotely in an unseeded wind tunnel. The system is able... more A coherent lidar was used to detect sound remotely in an unseeded wind tunnel. The system is able to reconstruct acoustic temporal waveforms by detecting the motion of natural aerosols. The acoustic motions were measured in the presence of much larger motions caused by the ambient fluid-dynamic turbulence. Unlike conventional microphones, remote acoustic sensing is immune to wind-induced self-noise and avoids disturbing the aerodynamic flow. By forming a virtual microphone array it is possible to make the lidar system directional, thereby rejecting acoustic reflections from wind tunnel walls. The system employs a continuous-wave, single-frequency, 1.55 µm fiber laser in a bistatic configuration and a heterodyne receiver with a 200 MHz intermediate frequency. The acoustic waveform was impulsive, characteristic of acoustic signatures of helicopters. There is close agreement between the lidar and conventional microphone signals.
Journal of The Optical Society of America B-optical Physics, 1986
A one joule, 60 ns, XeCl laser pulse was compressed to 6 ns (FWHM) by a phase-conjugated, stimula... more A one joule, 60 ns, XeCl laser pulse was compressed to 6 ns (FWHM) by a phase-conjugated, stimulated-Brillouin-scattering compressor in SF6 with an efficiency of 50%. The Stokes seed beam was generated by focusing the pump beam into a Brillouin cell.
American Journal of Physics, 1983
Journal of The Optical Society of America B-optical Physics, 1986
Journal of The Optical Society of America, 1979
The frequency drift of the modes of a XeCl laser oscillator was deduced by measuring the contrast... more The frequency drift of the modes of a XeCl laser oscillator was deduced by measuring the contrast of fringes produced by the laser in a Michelson interferometer. A calculation of the drift produced by the time-dependent refractive index of the gain medium is in reasonable agreement with the measured value.
The Astrophysical Journal, 1987
The Astrophysical Journal, 1981
A coherent lidar was used to detect sound remotely in an unseeded wind tunnel. The system is able... more A coherent lidar was used to detect sound remotely in an unseeded wind tunnel. The system is able to reconstruct acoustic temporal waveforms by detecting the motion of natural aerosols. The acoustic motions were measured in the presence of much larger motions caused by the ambient fluid-dynamic turbulence. Unlike conventional microphones, remote acoustic sensing is immune to wind-induced self-noise and avoids disturbing the aerodynamic flow. By forming a virtual microphone array it is possible to make the lidar system directional, thereby rejecting acoustic reflections from wind tunnel walls. The system employs a continuous-wave, single-frequency, 1.55 µm fiber laser in a bistatic configuration and a heterodyne receiver with a 200 MHz intermediate frequency. The acoustic waveform was impulsive, characteristic of acoustic signatures of helicopters. There is close agreement between the lidar and conventional microphone signals.
Journal of The Optical Society of America B-optical Physics, 1986
A one joule, 60 ns, XeCl laser pulse was compressed to 6 ns (FWHM) by a phase-conjugated, stimula... more A one joule, 60 ns, XeCl laser pulse was compressed to 6 ns (FWHM) by a phase-conjugated, stimulated-Brillouin-scattering compressor in SF6 with an efficiency of 50%. The Stokes seed beam was generated by focusing the pump beam into a Brillouin cell.
American Journal of Physics, 1983
Journal of The Optical Society of America B-optical Physics, 1986
Journal of The Optical Society of America, 1979
The frequency drift of the modes of a XeCl laser oscillator was deduced by measuring the contrast... more The frequency drift of the modes of a XeCl laser oscillator was deduced by measuring the contrast of fringes produced by the laser in a Michelson interferometer. A calculation of the drift produced by the time-dependent refractive index of the gain medium is in reasonable agreement with the measured value.