Chapter 12
Nonlinear Label-Free Super-Resolution
Microscopy Using Structured
Illumination
Mikko J. Huttunen and Antti Kiviniemi
Abstract Optical microscopy is a standard tool to study biological objects. Diffraction limits the achievable lateral resolution of an optical microscope to around 200
nm restricting its applicability. However, recent advances in optical super-resolution
techniques have shown that the diffraction does not impose a fundamental limit to
resolution and can be circumvented. These super-resolution techniques can provide
resolution approaching the nanometer scale and are enabling studies of biological
objects with unprecedented capabilities. However, most of the super-resolution techniques are based on using fluorescent dyes, complicating their use in medical research
and applications. Therefore, a need exists for label-free super-resolution techniques,
which could be especially valuable for clinical applications. To answer this need,
several such techniques have been recently developed. In this chapter, we introduce
the reader to some of these techniques, discuss their applications, and of the possible
future directions. In order to limit the scope of this vastly expanding topic, we focus
on techniques based on structured illumination and intrinsic nonlinear responses of
materials.
12.1 Introduction
Optical and electron microscopies are de facto tools for studying biological objects.
Electron microscopy provides superior resolution [1], but requires more complicated instrumentation and sample preparation restricting its applicability [2]. Optical
microscopy, on the other hand, provides coarser resolution, but is related with simpler
sample preparation, capability for three-dimensional (3D) imaging and can be easily
used to study living objects [3]. These advantages have made optical microscopy an
indispensable tool for biological and medical research.
M. J. Huttunen (B) · A. Kiviniemi
Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland
e-mail: mikko.huttunen@tuni.fi
A. Kiviniemi
e-mail: antti.kiviniemi@tuni.fi
© Springer Nature Switzerland AG 2019
V. Astratov (ed.), Label-Free Super-Resolution Microscopy,
Biological and Medical Physics, Biomedical Engineering,
https://doi.org/10.1007/978-3-030-21722-8_12
289
Nonlinear Label-Free Super-Resolution
Microscopy Using Structured
Illumination
Mikko J. Huttunen and Antti Kiviniemi
Abstract Optical microscopy is a standard tool to study biological objects. Diffraction limits the achievable lateral resolution of an optical microscope to around 200
nm restricting its applicability. However, recent advances in optical super-resolution
techniques have shown that the diffraction does not impose a fundamental limit to
resolution and can be circumvented. These super-resolution techniques can provide
resolution approaching the nanometer scale and are enabling studies of biological
objects with unprecedented capabilities. However, most of the super-resolution techniques are based on using fluorescent dyes, complicating their use in medical research
and applications. Therefore, a need exists for label-free super-resolution techniques,
which could be especially valuable for clinical applications. To answer this need,
several such techniques have been recently developed. In this chapter, we introduce
the reader to some of these techniques, discuss their applications, and of the possible
future directions. In order to limit the scope of this vastly expanding topic, we focus
on techniques based on structured illumination and intrinsic nonlinear responses of
materials.
12.1 Introduction
Optical and electron microscopies are de facto tools for studying biological objects.
Electron microscopy provides superior resolution [1], but requires more complicated instrumentation and sample preparation restricting its applicability [2]. Optical
microscopy, on the other hand, provides coarser resolution, but is related with simpler
sample preparation, capability for three-dimensional (3D) imaging and can be easily
used to study living objects [3]. These advantages have made optical microscopy an
indispensable tool for biological and medical research.
M. J. Huttunen (B) · A. Kiviniemi
Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland
e-mail: mikko.huttunen@tuni.fi
A. Kiviniemi
e-mail: antti.kiviniemi@tuni.fi
© Springer Nature Switzerland AG 2019
V. Astratov (ed.), Label-Free Super-Resolution Microscopy,
Biological and Medical Physics, Biomedical Engineering,
https://doi.org/10.1007/978-3-030-21722-8_12
289