| We have studied the fabrication and packaging of semiconductor lasers and amplifiers and, in particular, have concentrated our efforts on superluminescent diodes (SLD's). High power, broad spectral width and small spectral modulation light sources can be obtained by optimizing the epitaxial design, the waveguide design and the mounting of these devices. Angled-facet single mode active waveguide devices with freely propagating absorption region made from optimized active epitaxy-layers led to a SLD with good performances. As much as 20 mW optical power in a more than 130 nm bandwidth was obtained with less than 0.2 dB spectral modulation. It is shown by both experimental results and numerical calculation that more optical power can be obtained, at the expense of the spectral width, by using longer devices. Most of the applications of these devices require an efficient and stable coupling of light from the device to the optical fiber. For this purpose, a lens can be fabricated at the end of the optical fiber to improve the coupling efficiency. Chemically etched conical fibers and wedge shape angled front fibers were fabricated and optimized for high coupling efficiency. For obtaining stable coupling in a compact package, an optical fiber should be rigidly fixed to maintain the aligned position with respect to the SLD. Packaging of a laser diode with a single mode optical fiber was realized using ultra-violet (UV)-curable epoxy and silicon waferboard with micro-machined V-groove. A simple thermo-mechanical model of this approach was analyzed with a finite element method. Both epitaxy-side down mounting of semiconductor device with good yield and thermal resistance measurement technique for mounted superluminescent diode were developed. |
