Nicht angegeben.This Master thesis was performed around an experiment aiming at the investigation of the optical properties of laser cooled Cesium (Cs) atoms dipole trapped in the evanescent field of an optical nanofiber. Two parts of the total experiment are covered in this thesis. The focus of the first part is the beam preparation of the EIT control and probe lasers which ensures a phase stable joint performance of both beams necessary for the implementation of EIT. This is achieved by an optical phase-locked loop (OPLL) locking the probe to the control laser. The performance of this OPLL is examined with an out-of-loop phase noise measurement.
The second part of this thesis concerns the efficient detection of the prospective few-photon EIT probe signal, which will be immersed in a broadband noise background. While the weak EIT probe signal (<pW power) is expected to be extremely narrow-band (<kHz) the noise has a power of ~5pW within a wavelength window of 10nm around the probe wavelength. Conventional optical filters fail in efficiently separating the signal from the fluorescence. Here, two strategies are elaborated theoretically aiming at a reasonable solution for narrow-band few-photon filtering: one employing a diffraction grating and another based on homodyne detection. Experimental proposals for filters based on both options are made, followed by an experimental realization and analysis of a compact test setup, a homodyne saturation spectroscopy
