Lasing from InP Nanowire Photonic Crystals on InP Substrate

2D photonic crystal (PhC) lasing from an InP nanowire array still attached to the InP substrate is demonstrated for the first time. The undoped wurtzite InP nanowire array is grown by selective area epitaxy and coated with a 10 nm thick Al2O3 film to suppress atmospheric oxidation and band-bending effects. The PhC array displays optically pumped lasing at room temperature at a pulsed threshold fluence of 14 mu J cm(-2). At liquid nitrogen temperature, the array shows lasing under continuous wave excitation at a threshold intensity of 500 W cm(-2). The output power of the single mode laser line reaches values of 470 mu W. Rate equation calculations indicate a quality factor of Q approximate to 1000. Investigations near threshold reveal that lasing starts from isolated islands within the pumped region before coherently merging into a single homogeneous area with increasing excitation power. This field emits a lasing mode with an average off-normal angle of approximate to 6 degrees. Single mode lasing with the nanoarray still attached to the InP substrate opens new design opportunities for electrically pumped PhC laser light sources.

Automated summary

This study demonstrates 2D photonic crystal lasing from an InP nanowire array still attached to the InP substrate, achieving lasing at room temperature and liquid nitrogen temperature. Investigations near threshold reveal the effects of excitation power on lasing initiation and emission mode transition.