Grating-assisted glass waveguide devices and fiber -optic parametric amplifiers for optical communication systems.

Abstract

The theory, design, and implementation of several photonics devices for the generation, amplification, and processing of optical signals in optical communication systems are described. A cascaded fiber-optic parametric amplifier based on a quasi-phase matching technique is implemented. This cascaded implementation is the first explicit application of quasi-phase matching techniques to a fiber-optic parametric amplifier and results in a 12 dB gain enhancement using a 3-stage structure. For the generation and the wavelength-sensitive processing of optical signals, distributed Bragg reflector (DBR) waveguide devices are fabricated in un-doped and Er/Yb co-doped glass substrates using Ag<super>+</super> and K<super>+</super> ion-exchange, respectively. Wavelength-selective operation is realized by implementing the DBRs using a high refractive index overlay technique. This technique allows DBR fabrication on substrates with hard-to-etch surfaces and can produce very short, high efficiency reflectors by utilizing the enhanced interactions between the waveguide and the high index overlay DBR. The development of methods for overlay/waveguide design, thin-film characterization, and optimum thickness deposition are reported. Using this technique, an Er/Yb co-doped glass waveguide DBR laser with a 30 mW lasing threshold and a 8.5% slope efficiency is demonstrated. An optical add-drop multiplexer with a 24 dB transmission dip and a 0.5 nm wide 3 dB bandwidth is also designed and fabricated based on the same technique.