A Hybrid Transverse Mode Resonance DFB Semiconductor Laser

Abstract

We propose and theoretically analyze a hybrid transverse mode resonance DFB semiconductor laser which consists of one active section with π-phase shifted anti-symmetric Bragg grating (π-ASBG) and two passive sections with uniform Bragg grating. The hybrid light resonance along with mode conversion between the fundamental transverse electric (TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) mode and first order transverse electric (TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> ) mode is formed by the π-ASBG. The emitted light from one facet with the TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> or TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> mode can be controlled by tuning the injection currents of the passive sections. As an example, a laser with ridge waveguide is designed and simulated. The transverse mode with the same wavelength is tuned by changing the injection currents of the passive sections. The suppression ratio between the two transverse modes reaches 18.4 dB and 18.7 dB when the TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> and TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> modes are emitted, respectively. A simple method for equivalently realizing the grating in the proposed laser was also analyzed. Therefore, as the transverse mode tunable light source, the proposed laser may benefit the future mode division multiplexing (MDM) systems for reconfigurability and more flexibility.