Nanophotonics 2018; 7(12): 1971–1980
Research article
Luwei Wang
a
, Wei Yan
a
, Runze Li, Xiaoyu Weng, Jia Zhang, Zhigang Yang, Liwei Liu,
Tong Ye* and Junle Qu*
Aberration correction for improving the image
quality in STED microscopy using thegenetic
algorithm
https://doi.org/10.1515/nanoph-2018-0133
Received September 3, 2018; revised October 27, 2018; accepted
October 27, 2018
Abstract: With a purely optical modulation of fluores-
cent behaviors, stimulated emission depletion (STED)
microscopy allows for far-field imaging with a diffraction-
unlimited resolution in theory. The performance of STED
microscopy is affected by many factors, of which aberra-
tions induced by the optical system and biological sam-
ples can distort the wave front of the depletion beam at
the focal plane to greatly deteriorate the spatial resolution
and the image contrast. Therefore, aberration correction is
imperative for STED imaging, especially for imaging thick
specimens. Here, we present a wave front compensation
approach based on the genetic algorithm (GA) to restore the
distorted laser wave front for improving the quality of STED
images. After performing aberration correction on two types
of zebrafish samples, the signal intensity and the imaging
resolution of STED images were both improved, where the
thicknesses were 24 μm and 100 μm in the zebrafish retina
sample and the zebrafish embryo sample, respectively. The
results showed that the GA-based wave front compensation
approach has the capability of correction for both system-
induced and sample-induced aberrations. The elimination
of aberrations can prompt STED imaging in deep tissues;
therefore, STED microscopy can be expected to play an
increasingly important role in super-resolution imaging
related to the scientific research in biological fields.
Keywords: aberration; adaptive optics; genetic algorithm;
super-resolution imaging.
1 Introduction
Due to the nature of light diffraction, the lateral resolution
of a light microscope is limited to approximately half the
wavelength, which is typically equivalent to 200–350nm
in the visible light region [1, 2]. Fortunately, the advent of
fluorescence-based super-resolution microscopy (SRM)
techniques makes it possible for us to observe the details
of nano-scale structures such as viruses and subcellular
structures and may eventually transform our view of cel-
lular and molecular biology [3–5]. As one of the powerful
SRM techniques, stimulated emission depletion (STED)
microscopy has made significant achievements in bio-
medicine and in many relevant applications [6–9]. Com-
pared with other SRM techniques, including stochastic
optical reconstruction microscopy [10, 11], photoactivated
localization microscopy [12, 13], and structured illumina-
tion microscopy [14, 15], STED microscopy has the advan-
tages of relatively simple sample preparation procedures
and a fast imaging speed with no post-reconstruction
required. In STED microscopy, super-resolution imaging
is achieved by superimposing a donut-shaped depletion
focus on a Gaussian excitation focus. The donut-shaped
laser beam (called the depletion beam) at the red-shifted
wavelength relative to the peak of the emission spectrum
suppresses the fluorescence at the periphery of the exci-
tation focus spot to effectively narrow the point spread
function (PSF) below the diffraction limit.
a
Luwei Wang and Wei Yan contributed equally to this work.
*Corresponding authors: Tong Ye, Department of Bioengineering
and the COMSET, Clemson University, Clemson, South Carolina
29634, USA, e-mail: ye7@clemson.edu; and Junle Qu, Key
Laboratory of Optoelectronic Devices and Systems of Ministry of
Education and Guangdong Province, College of Optoelectronic
Engineering, Shenzhen University, Shenzhen 518060, P.R. China,
e-mail: jlqu@szu.edu.cn
Luwei Wang, Wei Yan, Xiaoyu Weng, Jia Zhang, Zhigang Yang and
Liwei Liu: Key Laboratory of Optoelectronic Devices and Systems
of Ministry of Education and Guangdong Province, College of
Optoelectronic Engineering, Shenzhen University, Shenzhen
518060, P.R. China. http://orcid.org/0000-0002-0745-9514 (W. Yan)
Runze Li: State Key Laboratory of Transient Optics and Photonics,
Xi’an Institute of Optics and Precision Mechanics, Chinese Academy
of Sciences, Xi’an 710119, P.R. China
Open Access. © 2018 Tong Ye and Junle Qu et al., published by De Gruyter.
This work is licensed under the Creative Commons Attribution-
NonCommercial-NoDerivatives 4.0 License.
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