研究了硬边环带光阑内外半径和衰减因子对环带光阑圆形艾里光束(CAB)自聚焦特性的影响。结果表明,控制环带光阑内外半径,可以增加CAB第一个自聚焦峰光强且抑制传播后续聚焦峰光强;和无光阑时相比,添加环带硬边光阑有聚焦峰光强在不同的衰减因子下普遍增强的优点。因此,该方法在光操控粒子方面具有潜在的应用。

利用光学注入锁定制备的拉曼激光可以用于原子干涉仪。为解决原子干涉条纹的相位受相位噪声的极大影响的问题,研究了不同实验条件下的拉曼激光相位噪声。采用光纤电光调制(EOM)和注入锁定相结合的方法得到两束频差为6.834 GHz的相位锁定拉曼激光,将主激光通过光纤EOM移频 6.834 GHz后作为种子光注入到从外腔半导体激光器,调节从激光器,获得-1级移频光的初步放大激光。结果显示,拉曼激光的拍频线宽不大于3 Hz,频率可调范围为300 MHz,主激光锁频下相位噪声在10 Hz~100 kHz范围内低于-60 dBc/Hz。

在原子干涉仪、原子陀螺仪等精密测量的领域中, 最基本也是最重要的一步就获得冷原子, 而当实验需要连续和高重复性的测量时, 对于冷原子的装载就会要求有更快的速率。为了能更快的装载冷原子, 就需要一束高通量、低速的冷原子束。在实验上实现了87Rb原子的二维冷却磁光阱(2D-MOT)的冷原子束, 其对3D-MOT的装载率为2.8×109 atoms/s。该系统基于87Rb原子2D-MOT+push beam方案, 选择了红失谐为20 MHz功率为50 mW的两束入射冷却光, 在冷却光入射到真空腔之前使用扩束系统将其光斑扩束成短轴为25 mm、长轴为75 mm的椭圆形光斑, 在冷却光入射真空腔之后在真空腔的另一端用镀了四分之一波片膜的反射镜来得到对射的激光。

Calcium is one prospective element for the modern optical frequency standard. The 423-nm transition line of calcium atoms has been widely used in laser slowing and laser cooling, the precise spectrum measurement, and the magnetic optical trapping (MOT). However, there is no any available commercial diode laser working at this wavelength. We built a 423-nm laser based on extra bow-tie cavity and by using a Brewster-cut uncoated BIBO (BiB3O6) crystal, which worked at room temperature, with conversion efficiency of 3.75%, and a potential up to 20%.

A compact extended cavity diode laser (ECDL) system operating at 852 nm for small optically pumped cesium (Cs) beam frequency standards was reported. ECDL and a saturated absorption spectroscopy setup were all built in an aluminum box with dimension of 10*10*7 (cm). ECDL was based on a Littman-Metcaff configuration, whose free-running linewidth was less than 600 kHz. A digital automatic frequency lock unit (AFLU) was developed to lock the laser frequency to specify Cs absorption lines automatically and re-lock it in case of lock broken. With AFLU, the laser frequency was continuously locked for several weeks.

Operating a laser diode in an external cavity, which provides frequency-selective feedback, is a very effective method to tune the laser frequency to a range far from its free running frequency. For the Ca atomic Ramsey spectroscopy experiment, we have constructed a 657-nm laser system based on the Littman-Metcalf configuration with a 660-nm commercial laser diode. Continuously 10-GHz tuning range was achieved with about 100-kHz spectral linewidth, measured with beat-note spectrum of two identical laser systems.

The matrix eigenvalue method is used to analyze a laser resonator composed of diffraction optical elements. The results show that this type of resonator can separate fundamental mode and high order modes effectively. The output beams can be designed for different requests.