Characterization of a distributed feedback laser with air/semiconductor gratings embedded by the wafer fusion technique

Wafer fusion between patterned or structured wafers is very useful in the c onstruction of new optical materials and/or devices that have submicrometer -order structures inside semiconductors. In order to investigate the feasib ility of wafer fusion for this purpose, a distributed feedback (DFB) laser was developed which has air/semiconductor gratings that are embedded using the wafer fusion technique. In this paper, the characteristics of the newly developed DFB laser and the coupling coefficient are investigated. Single- longitudinal-mode oscillation at 1.28 mu m is achieved under pulsed conditi ons at room temperature with a low threshold current density of 1.3 kA/cm(2 ), and the coupling coefficient is estimated to be approximately 100 cm(-1) . In addition, high-power surface emission (over 6 mW) is demonstrated due to the large difference between the refractive index of air and that of InP , These results indicate the feasibility of applying wafer fusion technique s to form submicrometer structures in semiconductors, and several other app lications are expected.