Radiative characteristics of a single-channel GaAs injection laser

An investigation was made of the radiative characteristics of gallium arsenide laser diodes with a luminous region several microns in size. A special feature of these lasers was that they emitted a single longitudinal mode in a wide range of injection currents at 77°K. The maximum output power in this mode was ~50 mW in the cw regime. The output was highly coherent: the coherence length exceeded 10 m. A comparison was made of the energy characteristics of the lasers with active regions 6 and 200 μ wide, operating in the single-frequency regime. Single-channel lasers were found to be 10 times as effective in conversion of electrical energy into coherent radiation than wide diodes.