Novel Atomic Mirror with a Blue-Detuned Semi-Gaussian Beam

A novel and simple atomic mirror composed of a blue-detuned
semi-Gaussian beam is proposed. From the Fresnel diffraction theory, the intensity distributions of a collimated Gaussian laser beam diffracted by the straight edge of a semi-infinite opaque plate are studied. The optical potential of the semi-Gaussian beam for ⁸⁵Rb atoms and its spontaneous emission probability are calculated and compared with the performance of the evanescent-wave mirror. Our study shows that the blue-detuned semi-Gaussian beam, as a novel atomic mirror, can be used to reflect atomic beam efficiently, and under the same beam parameters and lower normal atomic velocity, the performance of the semi-Gaussian-beam mirror is better than that of the evanescent-wave mirror.