Boef A J
Appl Opt. 1988 Jan 15;27(2):306-11. doi: 10.1364/AO.27.000306.
A two-wavelength interferometer is described that can be used to measure distances to rough surfaces with micrometer resolution. The measuring range can be made as large as several centimeters. Owing to the small numerical aperture of the object beam, the interferometer is particularly suitable in applications where a long working distance is required. The interferometer uses two single-frequency diode lasers to create a virtual two-wavelength laser. The equivalent wavelength of this laser can be easily tuned by changing the temperature of the laser diodes in opposite directions.
描述了一种双波长干涉仪，它可用于以微米分辨率测量到粗糙表面的距离。测量范围可达几厘米。由于物光束的数值孔径小，该干涉仪特别适用于需要长工作距离的应用。该干涉仪使用两个单频二极管激光器来产生虚拟双波长激光。通过沿相反方向改变激光二极管的温度，可以轻松调节该激光的等效波长。
