Abstract
The light field microscope has the potential of recording the 3D information of biological specimens in real time with a conventional light source. To further extend the depth of field to broaden its applications, in this paper, we proposed a multifocal high-resistance liquid crystal microlens array instead of the fixed microlens array. The developed multifocal liquid crystal microlens array can provide high quality point spread function in multiple focal lengths. By adjusting the focal length of the liquid crystal microlens array sequentially, the total working range of the light field microscope can be much extended. Furthermore, in our proposed system, the intermediate image was placed in the virtual image space of the microlens array, where the condition of the lenslets numerical aperture was considerably smaller. Consequently, a thin-cell-gap liquid crystal microlens array with fast response time can be implemented for time-multiplexed scanning.
Highlights
Based on the same structure as the conventional optical microscope, the light field microscope (LFM) was proposed [1,2,3]
The working range still limit the applications of light field microscope
The HiR LC-microlens array (MLA), which is coated with a high resistance layer of Nb2O5, has more symmetric lens profile and lower driving voltage than the conventional liquid-crystal microlens array (LC-MLA)
Summary
Based on the same structure as the conventional optical microscope, the light field microscope (LFM) was proposed [1,2,3]. In conventional optical microscope systems, the most straightforward solution to extend the working range is that axial-scanning the specimen by tuning the position or the effective focal length of the objective lens [27, 28]. It will induce non-uniform magnification and resolution issues in the LFM systems. The multi-focus MLA induces large blinds area between adjacent elemental images under the MLA because the effective microlens pitch becomes larger Another solution is using electrically tunable devices, such as a liquid lens or liquid-crystal microlens array (LC-MLA), to adjust the effective focal length of the MLA [35, 36]. Compared with the confocal microscopes, which require a slow mechanical scanning process to record 3D objects, the proposed LFM with multifocal HiR LC-MLA can cover the larger working range with much less capturing time (3-5 frames only)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
