Laser operation (77 °K) of In1−xGaxP LPE p‐n junctions is demonstrated at λ∼5900 Å (2.10 eV, yellow). The junctions are prepared by the sequential growth (on GaAs1−yPy substrates) of first an n‐type layer and then a Zn‐doped p‐type layer (not compensated). During growth of the p‐type layer, Zn diffuses slightly (at reduced concentration) into the first layer, yielding a thin compensated active layer. The structure which results approximates in operation the behavior of a single heterojunction. Although the threshold for the laser operation of these devices is fairly high, it is demonstrated, nevertheless, that In1−xGaxP LPE grown junctions can be operated as lasers and, furthermore, at wavelengths λ ≲5900Å.