The Design Of Master Oscillator Diode Laser Amplifiers

Monolithically integrated master oscillator diode laser amplifiers show a great promise as a compact high-power diode laser source. These devices have demonstrated high power laser output with single frequency, diffraction limited laser quality.Distributed Bragg reflection (DBR) lasers are usually adopted as the master oscillator laser for high quality laser beam, but fabrication process of DBR lasers is complicated. We have proposed a new kind of master lasers with half-ring cavity structure, which is simple for process and easy to integrate with. We have numerically analyzed the single-model operation condition of the half-ring cavity laser and influence of the half-ring cavity structure on bending loss and threshold current density has been obtained. Radius of the half-ring cavity is chosen to be 900μm formaintaining a low threshold current.Tapered structure is commonly used for laser amplifiers. We have analyzed the influence of the linewidth enhancement factor and effective differential gain on the beam quality with the theoretical model for tapered amplifiers. We also designed the structure of tapered amplifiers. Near-field and far-field distribution have be experimentally studied.