1.) US 6,396,338: Variable delay line detector

A variable delay line detector is disclosed including a power splitter, a mixer and a variable delay line. Various devices are suitable for the variable delay line, such as a non-linear transmission line (NLTL). The variable delay line detector is real-time programmable, thus, making it suitable in applications where phase and/or frequency of the input signal varies. For instance, the variable delay line detector may be utilized as an inexpensive demodulator in a frequency hopped spread spectrum system.

2.) US2002/0191251: All optical switching routing system

An optical switching device routes an optical data packet. The optical data packet includes header bits, data bits and a reset bit. The header bits identifies the switch state for routing the data packet and specific routing information of the data packet. The header bits transmitted at an optical carrier frequency are different than those at the carrier frequency of the data bits. The reset bit resets the switch element processor to enable processing and routing of the next data packet. The frequency of a particular header bit affects the index of refraction of a Bragg grating associated with the detector. The output of the detector, which is provided to a switch, determines the routing path of the packet. A return command resets the diffraction grating to prevent disturbing subsequent header bits.