Theory of cascaded quarter wave shifted distributed feedback resonators

The theory of lambda /4 shifted DFB resonators, both series coupled and side coupled, is developed. The theory is limited to loss-free high-Q resonators. If the actual losses are too high, the internal losses of the structures, all of which are compatible with laser diode structures, can be compensated by gain via carrier injection. The theory of a simple transmission resonator is reviewed and extended to a side-coupled resonator.<
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