Synthetic wavelength stabilization for two-color laser-diode interferometry.
Synthetic wavelength stabilization for two-color laser-diode interferometry.
复制标题
双色激光二极管干涉测量的合成波长稳定。
作者：
P. D. de Groot;S. Kishner
传统干涉仪中的相位模糊可以通过使用两个不同光频率的激光二极管来产生合成波长来消除。然而，对于必须在大距离上提供光学条纹阶数的明确确定的双色干涉激光计的稳定性要求可能是严格的。我们推导出光波长的不确定性的上限，并表示它们作为一个函数的光程差之间的对象和参考光束，相位测量误差，和合成波长。提出了一种简单的稳定安排，涉及同时伺服控制的两个激光器与一个单一的Fabry-Perot étalon。该系统的实验实现证明了其有效性的长期（16小时）稳定的双色干涉超过250 mm的距离，与15 mm的合成波长和40 nm的重复性。对于< 1000 s的周期，重复性为8 nm。
The phase ambiguity in conventional interferometers can be removed by using two laser diodes of different optical frequencies to generate a synthetic wavelength. However, the stability requirements for a two-color interferometric laser gauge that must provide unambiguous determination of the optical fringe order over a large distance can be severe. We derive upper limits on the optical wavelength uncertainty and express them as a function of optical path difference between the object and reference beams, phase measurement errors, and the synthetic wavelength. A simple stabilization arrangement is proposed, involving simultaneous servo control of both lasers with a single Fabry-Perot étalon. The experimental implementation of the proposed system demonstrates its effectiveness for long-term (16-h) stabilized two-color interferometry over a distance of 250 mm, with a 15-mm synthetic wavelength and a repeatability of 40 nm. For periods of < 1000 s, the repeatability was 8 nm.