Theoretical Gain of Quantum-Well Wire Lasers

Gain is given theoretically for quantum-well wire lasers where electrons are confined one-dimensionally. Maximum gain is obtained for a quantum-well wire perpendicular to light propagation, due to anisotropy of the dipole moment. Although the density-of-states is infinite at subband edges, gain remains finite due to the intraband relaxation. Therefore, high gain can be obtained by reducing intraband scatterings. Gain in 100 Å×100 Å Ga_0.47In_0.53As/InP quantum-well wires is about twice that in 100 Å thick conventional quantum-wells, and reduction of the laser threshold is expected.