Rate equation reformulation including coherent excitation: application to periodic protocols based on spectral hole-burning

International audienceA large number of signal-processing protocols are based on recording a spectral pattern via spectral hole-burning in an inhomogeneously broadened absorption profile. We present a simulation method specifically designed for periodic excitation sequences leading to the creation of a spectral pattern. This method is applicable to any multi-level atomic structure. The atomic variables' coherent dynamics are solved for a single temporal excitation step. The result is expressed as an equivalent population transfer rate. This way, the whole sequence is described as a matrix product and the steady state of the system under periodic excitation is easily derived. The propagation through the atomic medium is fully decoupled from the temporal evolution. We apply this method to the engraving of a spectral grating in a large-absorption Tm:YAG sample for wideband spectral analysis

Investigation of strain-induced effects on microwave signals from an PM-EDF based short cavity DBR laser

Axial strain-induced effects on beating frequency from a short cavity PM-EDF based distributed Bragg reflector (DBR) laser was investigated and experimentally demonstrated for the first time. A linear strain sensitivity of 0.640 GHz/mε was obtained

Tunable Opto-Electronic Oscillator based on a Fiber-Ring Resonator and a dual-frequency laser

International audienceWe report on the first tunable opto-electronic oscillator based on a fiber ring resonator and a dual-frequency laser. The dual frequency optical signal is generated by a doubly tunable solid-state dual-frequency laser at telecom wavelength; both optical frequencies are electrically and independently tunable over more than 1 GHz bandwidth. The fiber-ring resonator is 25 meters long and its quality factor is close to 5.10 8 . One laser line is stabilized on a resonance of the resonator with a PDH servo-controller. The heterodyne beatnote, still tunable by adjusting the frequency of the other line, is locked with a so-called optical frequency-locked loop based on the same resonator. As a result, the beatnote is stabilized on the closest multiple of the free spectral range of the resonator. At 10 GHz, we measured a phase noise below -85 dBc/Hz at 10 kHz

In-situ Dispersion Measurement of a Coupled Optoelectronic Oscillator

International audienceWe present a direct measurement of the intracavity dispersion of a coupled optoelectronic oscillator (COEO). The measurement can be performed while the COEO is oscillating, taking into account the dispersion of the modulator and the saturated active medium, without any other component than the ones composing the oscillator. It eases the dispersion management before the detection stage for minimal amplitude-to-phase noise coupling

Oscillateur optoélectronique couplé bas bruit de phase à 10 GHz

National audienc

Experimental Design of a Low Phase Noise Coupled Optoelectronic Oscillator at 10 GHz

International audienceWe present an experimental study on two key elements to design a low phase noise coupled optoelectronic oscillator (COEO). Fiber lengths and dispersions are investigated to highlight the differences between the optical and optoelectronic loops. After optimization, a 10 GHz COEO at 1.5 μm with a total of 590 m of fiber exhibits phase noise levels of -125 dBc/Hz at 1 kHz and -140 dBc/Hz at 10 kHz

Low Phase Noise 10 GHz Coupled Optoelectronic Oscillator

International audienceWe present our recent results on a 10 GHz coupled optoelectronic oscillator (COEO). With a total of 550 m of fiber, the COEO exhibits phase noise level of -140 dBc/Hz at 10 kHz and -137 dBc/Hz for the first spur