Optical ADC Architecture for High-Rate RF Signal Sampling

The patent replaces the conventional electrical sampling head with an optical sampling system. Specifically, it uses a photodetector to convert optical signals to electrical signals, and employs an optical delay line to achieve time-domain sampling. This substitution of electrical components with optical components enables much higher sampling rates (up to GHz level) while maintaining reasonable system complexity through the use of integrated optical circuits.

The patent changes the fundamental operating parameter from electrical domain to optical domain. By using optical carriers instead of electrical signals for sampling, the system achieves higher bandwidth and faster response times. The optical frequency is much higher than electrical frequencies, enabling sampling rates that were previously unattainable with conventional electrical ADC architectures.

The patent segments the sampling process into multiple time slots using an optical delay line. Instead of using multiple parallel sampling heads, it uses a single photodetector that samples different portions of the input signal at different time delays. This time-division multiplexing approach achieves the same effective sampling rate as multiple parallel heads would provide, but with only one detector, thereby reducing device complexity.

The patent transitions from spatial parallelism (multiple sampling heads) to temporal sequencing (optical delay line). By introducing the time dimension through controlled optical delays, the system achieves high sampling rates through sequential sampling in the time domain rather than parallel sampling in the spatial domain, reducing the number of required components.