Nanocrystals with second harmonic response is a new class of nonlinear optical nanoprobes with dramatically different
properties from fluorescent agents. Compared with two-photon fluorescence, second harmonic generation is an ultrafast,
lossless, and coherent process. In particular, the absence of photobleaching and emission intermittency in the optical
response of the second harmonic nanoparticles is likely to complement the fluorescent agents widely used today in many
imaging applications. Furthermore, the coherent emission from the second harmonic generation process provides unique
opportunities for the application of coherence domain techniques that are not available with fluorescent agents. We
review the application of the second harmonic nanocrystals in imaging applications, especially those pertaining to
biomedicine.
We report the hydrothermal synthesis of free-standing lithium niobate nanowires. We show that the versatile properties
of bulk lithium niobate such as nonlinear optical effects can be exploited at the nanoscale. We describe the fabrication of
polydimethylsiloxane (PDMS) microfluidics as well as indium tin oxide (ITO) electrodes with different design for
dedicated applications. The control of microfluidic channel dimensions and the corresponding particle concentration is
explored. Finally, the selection of fluidic conductivity for optimal dielectrophoretic trapping conditions is discussed.
Surfaces -defined as the interfaces between solids and liquids- have attracted much attention in optics and biology, such
as total internal reflection imaging (TIRF) and DNA microarrays. Within the context of optofluidics however, surfaces
have received little attention. In this paper, we describe how surfaces can define or enhance optofluidic function. More
specifically we discuss chemical interfaces that control the orientation of liquid crystals and the stretching of individual
nucleic acids, diffractive and plasmonic nanostructures for lasing and opto-thermal control, as well as microstructures
that read pressure and form chemical patterns.
Applying electrical fields is a simple and versatile method to manipulate and reconfigure optofluidic devices. Several
methods to apply electric fields using electrodes on polymers or in the context of lab-on-a-chip devices exist. In this
paper, we utilize an ion-implanted process to pattern electrodes within a fluidic channel made of polydimethylsiloxane
(PDMS). Electrode structuring within the channel is achieved by ion implantation at a 40° angle with a metal shadow
mask. In previous work using the ion-implantation process, we demonstrated two possible applications in the context of
lab-on-a-chip applications. Asymmetric particles were aligned through electro-orientation. Colloidal focusing and
concentration was possible with negative dielectrophoresis. In this paper, we discuss the different electrode structures
that are possible by changing the channel dimensions. A second parameter of ion implantation dosage prevents the
shorting of electrodes on the side wall or top wall of the fluidic channel to the bottom. This allows for floating
electrodes on the side wall or top wall. These type of electrodes help prevent electrolysis as the liquid is not in direct
contact with the voltage source. Possible applications of the different electrode structures that are possible are discussed.
We propose a bacterial detection scheme which uses no biochemical markers and can be applied in a Point-of-Care
setting. The detection scheme aligns asymmetric bacteria with an electric field and detects the optical scattering.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.