Growth of AlN single crystals is achieved by physical vapor transport (PVT) in the reverse cone tungsten crucible, which
is induction-heated, for obtaining proper sublimation rate and ensuring effective heat and mass transport. In the
experiment, there is a little hole at the center of crucible lid where the temperature is lower than the periphery, and there
is a tungsten cover on the lid. A self-seeded AlN single crystal is grown due to the anisotropic growth property of AlN
crystals and limitation of the hole. During the following growth, the crystal as a seed becomes a large size and high
quality single crystal. By modified PVT, separate AlN single crystals with diameters of larger than 2mm on the crucible
lid have been obtained successfully for the first time.
Microchip-laser-pumped supercontinuum (SC) is successfully generated through a 30-m long photonic crystal fiber
(PCF). The spectra bandwidth of SC is 850 nm spanning from 550 nm to 1300 nm. The -15dB-flat bandwidth is 400 nm
spanning from 600 nm to 1000 nm. It is easy to achieve a much more flat SC with the sacrifice of spectra bandwidth. A
detailed simulation is carried out to help us understand more about the supercontinuum generation process. The primary
mechanism of spectral broadening is identified as parametric four-wave mixing (FWM) combined with stimulated
Raman scattering (SRS). These findings also demonstrate an effective way to generate a flat supercontinuum laser source.