Graduation date: 2006
Continuously tunable diode laser sources coupled to single-mode fiber are
useful sources for fiber Bragg grating (FBG) strain sensors. This paper describes the
development and fabrication of such a device. An introduction is given describing
applications of tunable lasers and some of the different methods of creating a tunable
diode laser. The design process and construction of the fiber Bragg grating-tunable
diode laser is described. A low-cost 1300 nm laser diode is anti-reflection coated with
a single layer SiO coating making it nearly a super-luminescent light emitting diode.
By coupling this coated laser to a short length of single-mode fiber containing a lowreflection
FBG, which serves as the new tunable laser output coupler, a tunable, fibercoupled
laser source is possible. The laser diode package is mounted in a temperaturecontrolled
mount, and the FBG is mounted so it can be strained. Due to the imperfect
antireflection coating continuous tuning is not possible. By controlling both
temperature and FBG strain, the laser can be continuously tuned across a 10 nm
spectral range giving a narrow line laser source for use in strain sensors.