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This study focuses on the effect of V-doping on the ferromagnetism (FM) of 6H—SiC powder. The X-ray diffraction results indicate that V is inserted into the 6H—SiC lattice. The Raman spectra reveal that with a V concentration of 25 ppm, the crystalline quality and carrier concentration of 6H—SiC are hardly varied. It is found that after the V-doping process, the saturation magnetization (Ms) and the vacancy concentration of 6H—SiC are both increased. From these results, it is deduced that the effect of V might contribute mainly to the increase of vacancy concentration, thus resulting in the increase of Ms of V-doped 6H—SiC.

Using a photonic crystal fiber with a zero dispersion wavelength of the fundamental mode at 780 nm designed and fabricated in our lab, the ultraviolet and mid-infrared continua are generated by cross-phase modulation between red-shift solitons and blue-shift dispersive waves. The dependences of continuum on the pump power and wavelength are investigated. With the pump working at 820 nm, when the pump power increases from 300 to 500 mW, the bandwidths of ultraviolet and mid-infrared continua change from 80 to 140 nm and 100 to 200 nm, respectively. The wavelength of ultraviolet continuum is below 246 nm, and the wavelength of mid-infrared continuum exceeds 2500 nm. Moreover, the influences of pump power on wavelength and conversion efficiency of different parts of continua are also demonstrated.

Undoped and V-doped 6H—SiC single crystals have been grown by the physical vapor transport method. The V concentration is determined to be 3.76 × 1017 at/cm3 and 6.14 × 1017 at/cm3 by secondary ion mass spectrometry for low V-doped and high V-doped SiC samples, respectively. The undoped 6H—SiC shows diamagnetism, while the V-doped 6H—SiC exhibits weak ferromagnetism. The lower V-doped sample shows stronger ferromagnetism compared to that of the higher V-doped sample. However, the structural characterization indicates that the lower V-doped SiC has a relative poor crystalline quality. It is found that both V dopants and defects are essential for introducing ferromagnetic exchange in V-doped SiC single crystals.