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Sensors for biomedical applications
This paper considers the impact during the last decade of modern IC technology, microelectronics, thin- and thick-film technology, fibre optic technology, etc. on the development of sensors for biomedical applications
Development of Photonic Crystal Fiber Based Gas/ Chemical Sensors
The development of highly-sensitive and miniaturized sensors that capable of
real-time analytes detection is highly desirable. Nowadays, toxic or colorless
gas detection, air pollution monitoring, harmful chemical, pressure, strain,
humidity, and temperature sensors based on photonic crystal fiber (PCF) are
increasing rapidly due to its compact structure, fast response and efficient
light controlling capabilities. The propagating light through the PCF can be
controlled by varying the structural parameters and core-cladding materials, as
a result, evanescent field can be enhanced significantly which is the main
component of the PCF based gas/chemical sensors. The aim of this chapter is to
(1) describe the principle operation of PCF based gas/ chemical sensors, (2)
discuss the important PCF properties for optical sensors, (3) extensively
discuss the different types of microstructured optical fiber based gas/
chemical sensors, (4) study the effects of different core-cladding shapes, and
fiber background materials on sensing performance, and (5) highlight the main
challenges of PCF based gas/ chemical sensors and possible solutions
Antenna-coupled silicon-organic hybrid integrated photonic crystal modulator for broadband electromagnetic wave detection
In this work, we design, fabricate and characterize a compact, broadband and
highly sensitive integrated photonic electromagnetic field sensor based on a
silicon-organic hybrid modulator driven by a bowtie antenna. The large
electro-optic (EO) coefficient of organic polymer, the slow-light effects in
the silicon slot photonic crystal waveguide (PCW), and the broadband field
enhancement provided by the bowtie antenna, are all combined to enhance the
interaction of microwaves and optical waves, enabling a high EO modulation
efficiency and thus a high sensitivity. The modulator is experimentally
demonstrated with a record-high effective in-device EO modulation efficiency of
r33=1230pm/V. Modulation response up to 40GHz is measured, with a 3-dB
bandwidth of 11GHz. The slot PCW has an interaction length of 300um, and the
bowtie antenna has an area smaller than 1cm2. The bowtie antenna in the device
is experimentally demonstrated to have a broadband characteristics with a
central resonance frequency of 10GHz, as well as a large beam width which
enables the detection of electromagnetic waves from a large range of incident
angles. The sensor is experimentally demonstrated with a minimum detectable
electromagnetic power density of 8.4mW/m2 at 8.4GHz, corresponding to a minimum
detectable electric field of 2.5V/m and an ultra-high sensitivity of
0.000027V/m Hz^-1/2 ever demonstrated. To the best of our knowledge, this is
the first silicon-organic hybrid device and also the first PCW device used for
the photonic detection of electromagnetic waves. Finally, we propose some
future work, including a Teraherz wave sensor based on antenna-coupled
electro-optic polymer filled plasmonic slot waveguide, as well as a fully
packaged and tailgated device.Comment: 20 pages, 16 figure
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