A Tunable Blue Light Source with Narrow Linewidth for Cold Atom Experiments

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2013,（4）
• 页码范围: 102-104
• 页数: 3页
• 语种: 英文
• DOI: 10.1088/0256-307X/30/4/044209

摘要

In last few years using short wavelength light to trap[1] and to manipulate atom is playing a more and more important role in cold-atom physics,including scientific research and practical application.Bloch's group managed to dress a 87Rb atom in blue and red light,which is called a super lattice to reveal physical mechanisms of atom interaction.[2] In the Sr optical clock experiment,[3] a 461-nm light source with high stability and narrow linewidth is used for a firstorder slowing process.Ca+ ions have great applications in quantum manipulation and quantum computing areas.In several experiments,[4] researchers have successfully trapped and probed Ca+ ions by using a stable and tunable 397-nm light source.Although commercial laser diodes with 400 nm are available for external cavity diode lasers,the low power and bad transverse laser shape limits their applications in cold atom experiments.Second-harmonic generation (SHG) provides a solution to these kinds of lasers with better properties.SHG is a nonlinear optical process,which could generate coherent emission of frequency-doubling from an injection laser,from which one can obtain the laser from 250 nm to 550 nm.In this Letter,we present a frequency-doubling system that combines good mechanical shock resistance,narrow linewidth,and long-term locking stability.We establish two double-frequency systems using crystals with different lengths.The performances of the two systems are compared.We find that the conversion efficiency of the longer crystal is higher than the short one.Finally,we briefly discuss the crystal heating by fundamental laser.