Mode Selectivity in Bragg Reflection Waveguide Lasers

Bragg reflection waveguides (BRWs) have recently been proposed for the development of high performance single mode lasers and nonlinear frequency conversion devices. In this letter, we experimentally demonstrate single transverse photonic bandgap mode operation in a large core BRW laser with low threshold current density (~594 A/cm²) and high characteristic temperature (T₀ ~ 175 K). The mode selectivity is examined theoretically using the effective index method and experimentally via far field and gain spectra measurements. Mode competition is found to take place among the lateral modes despite the optical thickness of the core layer being larger than the wavelength.