Modele de bruit et correction de phase pour un spectrometre par transformation de Fourier pour le domaine des telecommunications optiques

This thesis studies the performances of a Fourier transform spectrometer for telecommunication applications. It may be used to characterize active and passive DWDM components as well as to perform accurate power and wavelength analysis of transmitters. To determine the instrument's performance, a noise analysis is performed and a complete numerical model is developed. The model simulates the thermal, shot noise sources at the photodetectors and front-end electronics as well as relative intensity noise from the measurement laser and quantization noise from the analog-to-digital converter. The numerical model also simulates scanning speed fluctuations, mechanical vibrations and relative intensity noise from the reference laser causing sampling jitter at the analog-to-digital converter. Because a practical interferogram signal will never be perfectly symmetrical, an auxiliary manipulation constituting phase correction must be performed. The topic of phase correction is covered in the text and examples of the algorithm's performance are given. Correlating measurements and simulation results shows that the instrument's performance is close to the numerical model's prediction. Improvements on the mechanical, optical and electrical design will permit the instrument to reach the shot noise limit.