All optical Quasi Light Storage: achievements and limitations

In this paper we consider the achievements and limitations of two methods for delaying the optical signals based on quasi light storage (QLS). These methods are very simple and offer high tunable storage times up to several thousand bits. We explore the potentials and limitations of both methods. Fiber based QLS is useful when high absolute delay is required and very small amounts of attenuation can be tolerated. Frequency-to-time-conversion based QLS can be used for delaying of very high bandwidth signals.