| Atom gyroscopes depend on atom interferometry which uses the wave character of atoms and interferometry happens between the inertial states of atoms. Interferometers using atoms rather than light can measure acceleration and rotation to extremely high precision. Because the de Broglie wavelength of atoms is very much shorter than light wavelength, atom interferometers have the potential to reach greater inertial sensitivity than their optical counterparts. However, atoms in room temperature own too large a wavelength to perform strong interferometry, so atoms need to be cooled first. The Magneto-Optical Trap is a popular way for cold atoms, and laser cooling and trapping is over simplified because of it. Also it is robust and compact in system assembling, thus making it an easy and inexpensive method even ordinary laboratory can get access to.This thesis focuses on the atomic source part of the whole new and compact atom gyroscope system, and a 2D+-MOT is designed for this purpose. Compared to the earlier 3D-MOT, there is no magnetic field along the longitudinal axial which can eliminate the magnetic influence on the atom interferometry area. And optics is more flexible than before, making it quite versatile when it comes to try new ideas on. Given the consideration for integration, we rebuilt the laser optics. Polarization-maintaining single mode fiber is used to connect different parts of the laser optics, so we can move and transport some or all of it whenever necessary without breaking it apart. All the acousto-optical modulators are software controlled and the RF drivers are collected in packages for compactness. The parameters optimizing job is done repeatedly until the best performed atomic beams are obtained. Last but not least, the stability character is analyzed with the help of stability monitoring system. Laser frequency and power stability is of critical importance for interferometry since it is totally based on laser-atom interactions, there is a need for profound understanding the working principal of external cavity diode laser and frequency locking techniques. Afterwards, Raman- Ramsey fringes with two π/2 Raman pulses and the π/2-π-π/2 Mach-Zehnder fringes are observed, and both are stable and strong. Primary results show a promising start for using interferometers as acceleration and rotation sensors.The magnetic field gradients in the xy-plane are about 10G/cm with 1.8A current for each of the coil, and further fine current adjustment is allowed. With total power intensity of 3.5 mW/cm~2 and 3Γ red detuning from resonance for cooling laser and 9 mW/cm~2 and 5Γ for pushing laser, the obtained cold atomic beams have as high a flux as 4.7×109 atoms/s. The narrow longitudinal velocity distributions with mean velocity are about 10m/s and full width at half maximum(FWHM) 2m/s. The sources are intense and highly collimated, and they meet with the demands very well. |
