In1−x Gax P:N Laser Operation (cw, 77°K) on the Nitrogen A-Line Transition in Indirect Crystals (x ≥ 0.74) and in Direct Crystals above the Fundamental Band Edge (x ≥ 0.71)

The laser operation (cw, 77°K) of In1−xGaxP on the nitrogen A-line transition in indirect crystals (x≥0.74) and in direct crystals above the fundamental band edge (x≤0.71) is reported (5450 and 5470 Å, respectively). Thin (1–5 μ) experimental samples are prepared from crystals grown from In solution by a modified Bridgman method. The crystals are doped with GaN or N from the quartz of the synthesis ampoule. The samples are mounted in a sandwich configuration with indium wetted onto a copper heat sink on one side and thin CdS (10–20 μ) and sapphire on the other side. The thin samples are volume excited in a tiny spot by an argon-ion laser focused through the sapphire window and the CdS spacer which, with the sample, forms a high-Q compound cavity.