Buried-heterostructure semiconductor Raman laser with threshold pump power less than 1 W

The low-power operation of a semiconductor buried-heterostructure Raman laser is reported. We are developing these devices for very wide-band optical communication in the terahertz frequency region. It has a structure with a GaP active layer and AlxGa1−xP cladding layers, which are grown by the temperature-difference method under controlled vapor pressure. By making the stripe width 30–40 μm, we have obtained a threshold pump power of 500 mW. A low-threshold semiconductor Raman laser can be pumped by semiconductor injection lasers. We have measured the optical loss of the waveguide and detected the contribution from scattering and leakage at heterointerfaces.