Very low threshold visible TS lasers

Fundamental transverse mode lasers with very low threshold currents have been realized by use of the modified terraced substrate (TS) geometry. The threshold currents of 250 μm cavity length lasers at room temperature are typically 20-30 mA for wavelengths around 750 nm. In the 710 nm laser, which is the shortest lasing wavelength in this work, the threshold is as low as 70 mA in CW operation. The 726 nm laser was operated for only 150 h, while a lifetime longer than 10 000 h is expected for TS lasers with a lasing wavelength longer than 750 nm.