Cheikh Ndiaye

Spectral Characteristics of a Frequency-Shifted Feedback Ring Laser Using a Semiconductor Optical Amplifier

We report the spectral characteristics of a frequency-shifted feedback laser using a semiconductor optical amplifier as a gain medium in a free-space ring cavity configuration. Oscillation bandwidths as broad as 130 GHz have been measured. Using self-delayed heterodyne interferometric experiments, we confirm the generation of a comb of chirped frequency components from this laser, with chirp rates faster than 85 PHz/s.

Long Range, High Accuracy Optical Ranging using Frequency-Shifted Feedback Lasers

Frequency-shifted feedback (FSF) laser generating a comb of chirped frequency components have great potential in long-distance and high-accuracy optical ranging applications. We confirmed that these lasers could achieve sub-mm accuracy, which was less affected by distance, up to 1 Km. A potential application of these lasers is in 3-D shape measurement.

Noise waveforms with repetitive phase and nonrepetitive amplitude.

By use of frequency-shifted feedback lasers, noise with a stationary amplitude and a periodically stationary phase is generated. The ensemble-averaged time correlation function is periodic, whereas the power spectrum is broadband, resulting in a waveform that does not obey the Wiener-Khintchine relations. An application to multiple-access communications is discussed.

1.5 μm band dual-wavelength pulse light source for THz-wave generation

Characteristics of a dual-wavelength light source based on intensity modulation of two continuous-wave tunable lasers operating in the 1.5 μm-band are reported. KW-order peak power synchronized optical pulses with widths and repetition rates of 170 ps and 1 MHz respectively were generated. Generation of THz-wave centered at 1.5 THz was demonstrated using a slanted-type PPLN.

Frequency-shifted feedback laser with an SOA

Generation of a chirped comb with chirp rate of 85 PHz/s across 130 GHz from a frequency-shifted feedback ring laser with semiconductor optical amplifier as gain medium is reported. Electronic tunability from 1535 to 1580 nm was measured.

A novel 3-D measurement technique using a frequency chirped laser

A novel 3-D measurement technique based on optical frequency-domain reflectometry which uses a frequency-shifted feedback laser as chirped light source is reported. Measurement ranges of 1m, accuracies better than 50μm and speed of 1000points/s have been demonstrated.