Rare-earth-doped glass Anderson localizing optical fibers (g-ALOF) have great potential for novel power, coherence, and spectral properties as the gain medium in fiber lasers. We report on our investigation of the optical properties of Yb-doped g-ALOF near the peak absorption wavelength, especially the localization, and lasing- and gain-related parameters. These include the fluorescence lifetime, emission cross-section, absorption cross-section, saturation power, gain, scattering loss, and background absorption. We also elaborate on several new measurement techniques that were required to obtain these parameters, mainly due to the substantial structural difference between g-ALOFs and conventional fibers.
An optical fiber-based microheater is described. The fiber, a highly Yb-doped (23.4wt% Yb2O3) silicate glass, can produce thermal power densities in excess of 10 W/nL via optical pumping at 976nm. No evidence of luminescence is observed, indicating efficient conversion from optical to thermal energy. Demonstrated are two applications for this microheater. The first is an all-optical-fiber Pirani thermal vacuum gauge, which uses a dual-fiber configuration. The second is an all-optically-driven, all-optical-fiber, Mach-Zehnder-based modulator. The phase delay, introduced by inserting the microheater into one interferometer arm, is a function of its temperature and can be actively controlled by the pump power.