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Listed below are
some of the projects which we are currently researching. Click
on the subject of interest. Related papers may also be
available under Publications.
Multiaxis
Fiber Grating Strain Sensors
High
Temperature Distributed Fiber Optic Sensors
Using
Multiaxis Fiber Gratings to Perform Health Monitoring on
Adhesive Joints
Fiber
Grating Sensors to Monitor the Manufacturing Process
High
Speed Fiber Grating Demodulation Systems
Bridge
Health Monitoring Projects
Panels
and Structures Capable of Measuring Multidimensional Strain
Fields
Fiber
Grating Pressure Sensors
Advanced
Communication Systems
Multiaxis Fiber
Grating Strain Sensors
Blue Road Research has been
developing a series of multiaxis fiber optic grating sensors with
support from Phase I and Phase II SBIR programs awarded by NASA
Langley. These efforts have resulted in the fabrication and test of
approximately 150 multiaxis fiber grating sensors with about half of
the units being sold commercially. These sensors are unique in that
they provide a convenient method to measure transverse strain,
transverse strain gradients as well as longitudinal strain and
temperature at a single point. Blue Road Research has a series of
issued and pending patents on this technology and is continuing to
work with several customers on structural and manufacturing
applications.
Papers covering aspects
of these developments are referenced in the Blue Road Research paper
bibliography that can be found on the Publications
page. Applications notes and a manual are currently in preparation.
Polyimide coated multiaxis fiber grating strain sensors are
available from BRR with performance parameters suitable for
structural and manufacturing applications (See the Products
page for specifications for fiber optic grating sensors).
Blue Road Research is
collaborating with Research International on an advanced version of
their ferret series of fiber grating demodulators to support
multiaxis fiber gratings as well as developing software supporting
optical spectrometers. For further details on Research International
products and the ferret please see our Products
page. 
High
Temperature Distributed Fiber Optic Sensors
Blue Road Research completed a
study for NASA Lewis on high temperature distributed fiber optic
sensors targeting aerospace applications. A report generated from
this effort is available.
Using
Multiaxis Fiber Gratings to Perform Health Monitoring on Adhesive
Joints
Blue Road Research completed a
Phase I SBIR for NAVAIR on using multiaxis fiber grating sensors for
health monitoring in 1998 and started work on a Phase II the second
quarter of 1999. This program allowed for the first time internal
diagnostics of multiaxis strain fields interior to an adhesive joint
in real time. During Phase II Blue Road Research is expanding and
extending the system toward supporting ground maintenance and
in-flight applications.
Fiber
Grating Sensors to Monitor Manufacturing Processes
Blue Road Research has used
fiber grating sensors to monitor the manufacture of fiber glass
utility poles (up to 60 feet in length), composite missile bodies
and thick composite panels made of experimental materials. Currently
work is being performed for the Army Research Lab under a Phase II
contract awarded to Production Products. For this program Blue Road
Research is using both single and multiaxis fiber grating strain
sensors as well as a new fiber grating demodulation system to
support this effort.
High
Speed Fiber Grating Demodulation Systems
Blue Road Research has
developed a series of high speed demodulation systems based on
chirped fiber gratings, overcoupled couplers and miniature
Mach-Zehnder interferometers. These demodulators which currently
operate at 10 kHz have been used to support testing under Oregon
Department of Transportation programs as well as those of the Army
Research Lab. Blue Road Research is currently looking at extensions
of this technology to speeds in the 1 to 10 MHz regime as well as
multiplexing several fiber grating sensors in line while retaining
high speed demodulation capability.
Bridge
Health Monitoring Projects
Blue Road Research has
installed 28 fiber grating sensors on the Horsetail Falls bridge in
the Colombia River Gorge of Oregon and with the Oregon Department of
Transportation and Oregon State University is engaged in a two year
program to assess these sensors for health monitoring. This project
is unique in that it studies composite-wrapped concrete beams with
fiber sensors placed in the composite wrap as well as in the
concrete beam. Blue Road Research also developed a small tubular
package that allows long gauge length fiber grating sensors to be
constructed that are small enough to be embedded in composite wrap.
Identical beams have been constructed as Oregon State University and
Blue Road Research has instrumented and supported testing of these
beams. This is one of the few times full scale bridge structures
have been tested in the lab and compared to structures in the field.
Blue Road Research and Smartec
have also installed two SOFO (Michelson interferometer based
sensors) on the Horsetail Falls bridge and are using them to compare
results of the long gauge length fiber grating sensors. For
information on the Horsetail Falls project please see the paper in
the Publications
section of this web
site. To see more details about Smartec sensors (Blue Road Research
is the US distributor of their products) Click
Here.
Panels
and Structures Capable of Measuring Multidimensional Strain Fields
As an outgrowth of its work on
multiaxis fiber grating strain sensors, Blue Road Research is
developing a series of structures that are capable of sensing shear
as well as transverse strain loads. One of the first developments in
this field is the smart load bearing intended for bridge structures.
The first unit has undergone a series of successful tests at the
Oregon Department of Transportation. It has multiaxis fiber grating
sensors placed in two locations to measure local transverse strain
fields and two placed to measure local shear strain. A paper on this
topic was presented at the SPIE Smart Structures/NDE Symposia in
Newport Beach, California in March 1999.
Fiber
Grating Pressure Sensors
Blue Road Research in
collaboration with Schlumberger have developed a series of fiber
optic grating pressure sensors that have the advantage of
temperature performance that is orders of magnitude superior to that
of using a fiber grating sensor directly to measure pressure. Two
patents related to this technology have issued and a paper on the
topic was presented at the Optical Fiber Sensors conference in April
1999 in Korea.
Advanced
Communication Systems
Blue Road Research is involved
in the development of advanced communication systems and devices
that support the fiber communications field. A recent development
involves a very low loss fiber optic switch that could be used to
re-route WDM signals. This development and others like it fall out
of Blue Road Research work on fiber optic sensors.
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