We report for the first time to our knowledge, the random laser emission from surface corrugated waveguides. Discrete lasing modes, super narrow spectral linewidth, and the existence of lasing threshold behavior have been observed. A theoretical model combining transfer matrix method and effective refractive index method was presented to explain the random lasing phenomena.
Heterostructural photonic band gap materials were fabricated by sol-gel technique. The heterostructure consists of two one-dimensional periodical photonic structures with different photonic stop bands. We found that the band gap of the heterostructure was extended obviously. The new band gap is the sum of the gaps of the two periodical structures. The results match well with that calculated by transfer matrix method. We also fabricated heterostructural three-dimensional photonic structures by sub-micron spheres self-assembling method, similar result was obtained which extended the concept from one dimension to three dimension.
Micro-ring cavity on glass fibers and molybdenum wires were fabricated. The cavities were Rh B doped organic-inorganic hybrid sol-gel films. Cavity quality factor as high as 5880 was obtained, which proves that organic-inorganic matrix are excellent materials for micro-cavity fabrication. For large cavity diameter, we observed clear whispering gallery modes that belongs to the same series. On the other hand, when cavity diameter reduced to 50 μm, higher order whispering gallery modes also appeared.