LAUSR

The impact of sulfur doping on broadband terahertz emission in GaSe single crystals was investigated by optical rectification with oo-o phase matching. The maximum peak value of THz radiation generated from S-doped 2.5 mass% GaSe is 28.3% larger than that of intrinsic GaSe with pump fluence of 637 mW cm−2 and azimuthal angle of 0o. The saturation of THz emission in S-doped 2.5 mass% GaSe is increased compared with that of intrinsic and S-doped 7 mass% GaSe. The results demonstrate that GaSe with appropriate S-doping concentration can effectively improve the broadband THz radiation and saturation.