Abstract
Integral microscopy is a 3D imaging technique that permits the recording of spatial and angular information of microscopic samples. From this information it is possible to calculate a collection of orthographic views with full parallax and to refocus computationally, at will, through the 3D specimen. An important drawback of integral microscopy, especially when dealing with thick samples, is the limited depth of field (DOF) of the perspective views. This imposes a significant limitation on the depth range of computationally refocused images. To overcome this problem, we propose here a new method that is based on the insertion, at the pupil plane of the microscope objective, of an electrically controlled liquid lens (LL) whose optical power can be changed by simply tuning the voltage. This new apparatus has the advantage of controlling the axial position of the objective focal plane while keeping constant the essential parameters of the integral microscope, that is, the magnification, the numerical aperture and the amount of parallax. Thus, given a 3D sample, the new microscope can provide a stack of integral images with complementary depth ranges. The fusion of the set of refocused images permits to enlarge the reconstruction range, obtaining images in focus over the whole region.
Highlights
The acquisition of the 3D information of volumetric objects has been extensively developed during the last few decades
By taking advantage of the characteristics of this new setup, we propose to capture a collection of integral images, each one corresponding to a different axial position of the object reference plan (ORP) of the microscope
In this paper we have proposed a new integral microscope with strongly enlarged depth refocusing
Summary
The acquisition of the 3D information of volumetric objects has been extensively developed during the last few decades. Integral imaging (InI), first proposed by Lipmann [1] in 1908, is a technique that permits the capture of spatial and angular information by means of an array of microlenses. The main drawback of every integral imaging system, including integral microscopes, is the low spatial resolution of the views, compared with the spatial resolution provided by a conventional microscope In this sense, many different solutions have been proposed [10,11]. New kinds of solutions are necessary to overcome this problem In this sense, in this paper we propose a new technique based on the insertion of a single electrically tunable liquid lens (LL) at the aperture stop (AS) of the integral microscope. The use of different kinds of dynamic elements has been proposed recently in integral imaging microscopy. The paper is organized as follows: Section 2 establishes the basic theory of an integral microscope and explains the main drawback in terms of depth of field; Section 3 presents the proposed method to enlarge the reconstruction range; Section 4 shows experimental data to validate the method; and Section 5 presents the main conclusions of our work
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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
