Abstract
The double‐current‐confinement channeled‐substrate planar (DCC‐CSP) laser, fabricated by the newly developed double etching technique, with channel width smaller than carrier diffusion length is demonstrated. In the majority of the 2‐μm DCC‐CSP lasers tested, linear light‐current relation and stable fundamental‐mode operation have been uniformly observed over the range of current tested (up to 3–5Jth). The lasers operate in single longitudinal mode with fixed emission wavelength up to 2.2Jth. The narrow‐channel DCC structure offers a method to relax the stringent design tolerance in the conventional CSP laser.