Active control of the spectral and temporal output characteristics of solid-state lasers through use of MEMS scanning micromirrors is presented. A side-pumped Nd:YAG laser with two intracavity scanning micromirrors, enabling Q-switching operation with controllable pulse duration and pulse-on-demand capabilities, is investigated. Changing the actuation signal of one micromirror allows a variation of the pulse duration between 370 ns and 1.06 μs at a pulse repetition frequency of 21.37 kHz and average output power of 50 mW. Pulse-on-demand lasing is enabled through actuation of the second micromirror. To our knowledge this is the first demonstration of the use of multiple intracavity MEMS devices as active tuning elements in a single solid-state laser cavity. Furthermore, we present the first demonstration of control over the output wavelength of a solid-state laser using a micromirror and a prism in an intracavity Littman configuration. A static tilt actuation of the micromirror resulted in tuning the output wavelength of an Yb:KGW laser from 1024 nm to 1031.5 nm, with FWHM bandwidths between 0.2 nm and 0.4 nm. These proof-of-principle demonstrations provide the first steps towards a miniaturized, flexible solid-state laser system with potential defense and industrial applications.
We report on the design and preliminary testing of an interferometric interrogator capable of large-scale time-division
multiplexing of FBG sensors. The scheme employs a passive algorithm for phase demodulation, allowing changes in
FBG sensor reflected wavelengths to be calculated instantaneously upon arrival, and incorporates a technique for
identification of initial absolute sensor wavelengths in order to overcome the measurement ambiguity associated with
interferometric schemes. The proposed system will allow for high-speed interrogation of large-scale FBG sensor arrays
with interferometric resolution and the capability for dynamic, static, and absolute FBG wavelength measurement.