Wavelength Conversion and Dispersion Compensation Using Cavity-Enhanced Four-Wave Mixing in Semiconductor Lasers.
In this dissertation, I have investigated several elements which can be used to construct a high-speed, multiple wavelength optical communication network. I have reported the first demonstration of an electrically-tunable mode-locked laser source consisting of an anti-reflection coated InGaAsP distributed-Bragg -reflector laser chip and a single-mode fiber extended cavity. Measured output pulses were as short as 14 ps. The maximum wavelength tuning range exceeded 8 nm. This laser was used to measure the temporal response of a wavelength converter which used cavity-enhanced four -wave mixing in an injection-locked semiconductor laser. The information bandwidth of the device was found to increase with decreasing bias current or increasing injected pump power. These measurements were in agreement with a two -mode rate equation analysis, and suggest that these wavelength converters could be used to switch multi-gigabit optical channels. I report satisfactory bit-error-rate performance of the wavelength converter for data rates of 2.5 and 10 Gb/s. Operation at 10 Gb/s exceeds the previous best result for this type of device by an order of magnitude. The 7.5-nm wavelength-conversion range corresponds to a frequency -conversion range of 0.94 THz. Using the mid-span spectral inversion technique, which exploits the phase-conjugate property of four-wave mixing, the wavelength converter was used to perform dispersion compensation in a 10-Gb/s 333-km long-haul optical transmission system over conventional single-mode fiber. The bit-rate times distance product of 3330 (Gb -km)/s surpasses the previous best result for a semiconductor device by more than a factor of 13.
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- Engineering: Electronics and Electrical; Physics: Optics