Polarization Control of Vertical-Cavity Surfaceemitting Lasers by Tilted-Etching of Cavity
AbstractWe performed a polarization control method for vertical-cavity surface-emitting lasers by tilted-etching of the air-post. Circular laser posts were etched by tilting the substrate toward [110] or [110] direction with an angle of 15° ˜ 20° using reactive ion beam etching. For the laser devices with a diameter of 7 ˜ 10 μm, we observed outstanding selectivity of the polarization state. We found a dominant polarization perpendicular to the tilted direction. The maximum orthogonal polarization suppression ratio was about 25 dB. The selectivity of polarization in the tilted laser post devices is interpreted to be originated from the difference of optical losses of the two waves polarized to the [110] and [110] directions.