Coupling of L-type photonic-crystal (PhC) cavities in a geometry that follows inherent cavity field distribution is exploited for demonstrating large mode splitting of up to similar to 10-20 nm (similar to 15-30 meV) near 1 mu m wavelength. This is much larger than the disorder-induced cavity detuning for conventional PhC technology, which ensures reproducible coupling. Furthermore, a microlaser based on such optimally coupled PhC cavities and incorporating quantum wire gain medium is demonstrated, with potential applications in fast switching and modulation. (C)2011 Optical Society of America