Quantum-Dot Lasers Exhibit High Characteristic Temperature

Researchers at the University of Texas at Austin have developed 1.3-µm InAs quantum-dot GaAs-based lasers whose characteristic temperature and low threshold current density may someday enable them to supplant InP-based lasers in fiber optic communications applications. For temperatures between 0 and 80 °C, the oxide-confined stripe lasers have a characteristic temperature of 213 K for pulsed operation and 196 K for CW. InP-based lasers typically have characteristic temperatures of less than 70 K. At room temperature, the quantum-dot lasers exhibit an output power of 15 mW and a CW threshold current density of 4.4 mA.

As reported in the September issue of IEEE Photonics Technology Letters, the researchers achieved these characteristics by P-type doping with beryllium the GaAs layers adjacent to the quantum-dot active layers.