基于原有的Littman结构外腔半导体激光器，提出采用一种新的光学方法来实现波长调谐。该方法采用了包含一个旋转楔形棱镜的“光杠杆”系统来降低调谐的机械要求，提高波长选择精度。通过选择不同的楔形棱镜顶角和光线入射角，机械要求可以降低1～2个数量级，波长选择精度也得到相同量级的提高。该方法使Littman结构外腔半导体激光器的调谐特性得到极大的改善，并大大降低了震动的敏感性。

On the basis of the traditional Littman external cavity diode laser,a novel optical method for wavelength tuning is proposed. A “refractive optical lever” system which consists of a rotating optical wedge prism is employed to reduce the requirement of the rotation mechanism for tuning and improve the accuracy of wavelength selection. By optimizing the vertex angle of the wedge prism and the incident angle of the light ray,the requirement of the rotation mechanism can be reduced by one or two orders of magnitude,and the wavelength selection accuracy can be improved as well. The characteristics of external cavity diode lasers are improved and its sensitivity to the vibration is reduced.