| In this dissertation we have investigated the design, development, and testing of etched-facet semiconductor lasers and amplifiers operating at a wavelength of 1.55 μm. We first studied the process development of reactive ion etched laser facets using a methane-based plasma. Utilizing a design of experiment (DOE) approach, and optimizing the parameters for verticality and etch rate, we were able to obtain laser facets with very high verticality, 2° +/− 0.7°, and an rms surface roughness of 22 nm, the best recorded to date for methane based facet etching.; We studied the long-term reliability of these etched facet lasers, in direct comparison to cleaved facet structures, by the use of a 70°C, 150 mA, 125 hour burn-in, followed by long-term testing of >2000 hours at 3mW output power. We found the room temperature mean-time-to-failure (MTTF) for the etched facets to be 75% of that of the cleaved devices, with values of 0.86 × 105 hrs and 1.15 × 105 hrs, respectively. The activation energy for the etched facet lasers was found to be 0.636 eV compared to 0.678 eV for cleaved devices.; Extending the work of the etched facet laser to amplifiers, we studied the development of a monolithically integrated bowed amplifier with v-groove fiber coupling assembly. We studied the formation of high-quality InP-based v-grooves using both oxidizing and acidic etches, taking advantage of the vertical or recessed endwall profile to allow close fiber coupling. Using 4 quantum well laser material, we were able to show broadband gain of over 12 dB for 1 mm, 2.6 μm ridge structures which closely resembles results from straight ridge devices. Utilizing the flexibility of fiber height control via the facet etching and v-groove profiles, we were able to control the lateral and transverse fiber position to within tenths of a micron. |
