(1. School of Flexible Electronics (Future Technologies), Nanjing Tech University, Nanjing 211816, China; 2. Shanghai AVIC Optoelectronics Co., Ltd, Shanghai 200245, China)
Abstract: To address the challenge of characterizing the morphology of large transparent and unstained samples that traditional bright-field microscopy cannot solve, a dark-field imaging system based on two-lens is proposed. The system primarily consists of a laser, a spatial light modulator, two lenses, and a charge-coupled device (CCD) camera. Ring-shaped vortex light modulated by the spatial light modulator serves as the illumination, focused onto the sample surface by the front lens. After illumination, the scattered light carrying high-frequency sample information was collected by the rear lens for dark-field imaging of the object. Experimental comparisons were conducted using sections of dicotyledonous wood and pumpkin stems as samples. The results indicated that a self-built dark-field microscopy system based on two-lens can enhance imaging resolution and contrast, offering a valuable approach for morphology characterization of large transparent and unstained samples.
Key words: two lens; vortex beam; dark field imaging; biological samples; morphological characterization
（Acta Laser Biology Sinica, 2024, 33(6): 523-529）