Modeling of InGaAsP-InP 1.55 mu m lasers with integrated mode expanders using fiber-matched leaky waveguides

A new concept for InGaAsP-InP 1.55 mum lasers integrated with spot size con verters using leaky waveguides is presented. The large fundamental mode siz e and the high discrimination of the higher order modes make ARROWs (Antire sonant Reflecting Optical Waveguides) and antiguided waveguides useful for fiber coupling functions. Three-dimensional (3-D) beam propagation method ( BPM) results show that the devices have transformation losses lower than 0. 22 dB. Fiber-coupling efficiencies of 60% are possible with standard cleave d single-mode fibers (SMF). The horizontal and vertical FWHM can be efficie ntly reduced to 9.70 degrees (horizontal) and 17.80 degrees (vertical). The fabrication of such devices avoids the growth of thick layers of quaternar y material with a low Ga and As fraction, and simplifies the fabrication to one planar epitaxial growth step and one non-critical conventional etch.