以笔者发现的激光频率分裂、模竞争、腔调谐等双折射双频激光物理效应，研制成激光器纳米测尺。激光器自身就是纳米量级位移传感器，利用腔内双折射元件把一个激光频率分裂成2个频率（⊥光模和∥光模）；当一腔镜沿激光器轴线移动并使这两个频率扫过激光增益区时，强烈和中等程度的竞争交替出现，把出光带宽分成3个等宽区间；合激光纵膜间隔为出光带宽的4/3时，在腔镜移动第一个λ/8波长内强竞争使⊥光模抑制掉∥光模，第二个λ/8波长内中度竞争使⊥光模和∥光模可一起振荡，第三个λ/8波长内强竞争使∥光模抑制掉⊥光模，第四个λ/8波长内⊥光模∥不振荡，激光器无光输出；4种状态重复一次，反射镜移动λ/2，计算出状态数，可知腔镜位移。由4个区域光偏振各不相同来判断腔镜位移方向。腔镜经一个机械测杆和被测物接触，实现被测物位移测量。测量范围已达15mm，分辩率79.08mm，线性度5×10^-6，重复性2σ优于0.314μm。该成果是激光技术和精密计量两领域交叉融合取得的自主原创性、有重要意义的突破性进展。

In the past applications saw laser as light source only, did not involve in internal structure and physical phenomena of lasers. The efforts had been done to transform single HeNe laser into a sensor, but ceased before great breakthrough. This paper reports the progress in investigating Laser Nano-meter Measurement Ruler, which is just the laser itself. The principle is based on the frequency splitting, mode competition, cavity tuning, etc., of laser, which are done or found by the author and colleagues. The configuration is that employing an inter — cavity birefringence element to split a laser frequency into two frequencies, ⊥light and // light; alternately occurring of strong and medium mode competition as the cavity being tuned, dividing the lasing bandwidth to three equivalent parts; again making the laser longitudinal separation being 4/3 of lasing bandwidth. The consequence is that 丄 light suppressing // light dying out in the first A /8 of mirror displacement, ⊥light and //light oscillating together in the second λ/8, //light suppressing ⊥light dying out in the third λ/8, ⊥light and //light dying out together in the fourth λ/8; with one time of repetition of the four regions the displacement of the mirror is λ /2. Calculating the number of polarization regions the displacement is known. The direction of displacement can be judged by the difference of polarization of each region. The cavity mirror of movement is joined with the object to be measured by a guide. The measurement range： 12 mm, resolution： 79.08 nm, linearity： 5×l0^-6, 2σ = 0.314 μm. This achievement is significant for both fields of lasers and metrology.