Low Threshold Single Mode Lasing from Suspended Membrane Photonic Crystal Surface Emitting Lasers

Low lasing threshold is desirable in photonic integrated circuits and many other applications in order to reduce the power consumption of the lasing device. Double lattice photonic crystal surface emitting laser utilizing constructive interference between the two lattices can be used to realize lower lasing threshold compared to single lattice devices. Here we demonstrate single mode lasing of a double lattice device and compare to its single lattice counterpart. The device is made of a suspended membrane of InP photonic crystal layer on InP substrate. The average lasing threshold values measured for four single and four double lattice devices were about 43 μJ/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 20 μJ/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> respectively. This work paves the way to successful realization of low threshold single mode PCSELs for different applications.