The fringe projection technique is considered one of the most reliable solutions for structured light technology, developed for non-contact three-dimensional (3D) data acquisition. When working with this technique, applying it on a microscopic scale, one often encounters some problems such as the limited depth of field of the projected fringe pattern, typical of the imaging lenses, or the formation of speckle-noise when laser interferometric fringes are projected, which are problems that can cause significant errors on test surfaces whose height exceeds the depth of field, and on which, the other hand, speckle noise affects the resolution of the technique. This paper presents a Gates’ interferometer configuration with a LED source to project a fringe pattern without speckle noise and a very long field depth. We explain how a non-located sinusoidal fringe pattern can be obtained using two-beamsplitter cubes and a LED light source. Moreover, we compare measurements made using the LED and laser concerning a commercial contact profilometer.

条纹投影技术被认为是结构光技术最可靠的解决方案之一，专为非接触式三维 (3D) 数据采集而开发。在使用这种技术时，在微观尺度上应用它时，经常会遇到一些问题，例如投影条纹图案的景深有限，典型的成像镜头，或者在投影激光干涉条纹时形成散斑噪声，这些问题可能会导致高度超过景深的测试表面出现重大错误，另一方面，散斑噪声会影响技术的分辨率。本文介绍了一种带有 LED 光源的 Gates 干涉仪配置，以投射没有散斑噪声和非常长的景深的条纹图案。我们解释了如何使用两个分束器立方体和一个 LED 光源获得非定位正弦条纹图案。此外，我们比较了使用 LED 和激光对商用接触式轮廓仪进行的测量。