离焦抖动优化技术不仅能消除投影仪的非线性误差,而且不受投影仪刷新率的限制。然而抖动算法本质上只是一个简单的矩阵变换,导致离焦后的二值抖动条纹并不完全接近正弦条纹,产生了一定的测量误差。基于此,提出了一种基于离散粒子群算法的优化方法,对二值离焦抖动技术进行优化。为了加快优化过程,用二值块的优化来代替整个二值图案的优化,然后再利用正弦条纹图案的周期性和对称性,将二值块拼成一个完整的图案。仿真和实验结果表明:所提方法在不同的离焦程度下,都能获得高质量的测量结果。

Recent developments in scanning holographic microscopy that offer the prospects of new quantitative tools and imaging modalities in bio, micro, and nano sciences are reviewed. The versatility of the method is emphasized. Scanning holography can operate in an incoherent mode for fluorescence imaging, in a coherent mode for quantitative phase imaging, or in a tomographic mode for axial sectioning and rejection of the out-of-focus haze. Possible applications are illustrated with examples, and future prospects are discussed.

We present a new optical microscope in which the light transmitted by a sample-scanned transmission confocal microscope is frequency-tripled by SiOx nanocrystallites in lieu of being transmitted by a confocal pinhole. This imaging technique offers an increased contrast and a high scattered light rejection. It is demonstrated that the contrast close to the Sparrow resolution limit is enhanced and the sectioning power are increased with respect to the linear confocal detection mode. An experimental implementation is presented and compared with the conventional linear confocal mode.