Photonic Crystal Diode Laser Array Integrated With a Phase Shifter for Narrow Beam Divergence

A narrow far-field edge-emitting photonic crystal diode laser array integrated with a phase shifter emitting in the 980-nm range has been designed and fabricated. A phase shifter structure is integrated on the chip to convert the out-of-phase mode to the in-phase mode. The real effective-refractive-index difference produced by the phase shifter is measured according to the comparison of the experiment and the simulation results. The effects of phase shifters with different lengths on the near and far fields are investigated. With the phase and the amplitude modulation of the phase shifter, the out-of-phase mode is successfully converted to the in-phase mode. Thus, a single-lobe far-field pattern is achieved in the lateral direction. The far-field divergence angles of the lateral and vertical directions are 1.5° and 12°, respectively. Such a device is promising for narrow far-field emission with a high output power.