Gain-cavity mode detuning vertical cavity surface emitting laser operating at the high temperature

The situation of vertical cavity surface emitting laser (VCSEL) operating at high temperature is analyzed theoretically, and the gain-cavity mode detuning characteristics is employed to design the epitaxy structure of VCSEL. The metal-organic chemical vapor deposition (MOCVD) growth and fabrication process are carried out. The barrier height above 0.25 eV is used in the active region of VCSEL to reduce the carrier leakage at high temperature. The designed structure employs the 11-nm gain-cavity mode deviation. The highest gain appeares at about 320 K, at which the minimum threshold current of VCSEL appears. The reflectivity of distributed Bragg reflector (DBR) within VCSEL is designed to obtain the low threshold current. The self-planar mesa structure is employed to fabricate the VCSEL devices. VCSEL with oxide apertures of 7, 9, 13 μm are fabricated. The threshold currents are 1.95, 2.53, 2.9 mA, respectively, and the corresponding maximum output powers are 0.31, 1.11, 1.04 mW at room temperature. The threshold current decreases first and then increased with the temperature increases, and the minimum value appears at 320-330 K. The measured results consist well with the gain-cavity characteristics of VCSEL.