Demonstration of blue semipolar (202¯1¯) GaN-based vertical-cavity surface-emitting lasers.

We successfully demonstrated an electrically injected blue(202¯1¯)semipolar vertical-cavity surface-emitting laser with a 5λ cavity length, an ion implanted aperture, and a dual dielectric DBR design. The peak power under pulsed operation was 1.85 mW, the threshold current was 4.6 kA/cm2 , and the differential efficiency was 2.4% for the mode at 445 nm of a device with a 12 µm aperture. Lasing was achieved up to a 50% duty cycle and the thermal impedance was estimated to be 1800 K/W. The lasing emission was found to be 100% plane polarized along the a-direction.