Apparatus for generating pulse train with adjustable time interval

An apparatus for generating a pulse train with an adjustable time interval, the apparatus being an annular optical cavity structure, the apparatus comprising:

• a seed source receiving end, for receiving an initial optical signal inputted;
• an optical coupler, having an input end serving as the seed source receiving end for receiving the seed source optical signal inputted, and another input end for cyclically transmitting the seed source optical signal within the annular optical cavity;
• an optical combiner, having an input end connected to an output end of the optical coupler, and another input end serving as a pump source receiving end for receiving a pump source optical signal inputted;
• at least one gain fiber, being a gain medium, located on the annular optical cavity structure, having at least one input end connected to an output end of the optical combiner, for amplifying a pulse train optical signal cycling within the annular optical cavity structure;
• an optical path time regulator, having an input end connected to an output end of the at least gain fiber, for adjusting the time interval between the pulse train optical signals within the annular optical cavity;
• and
• a beam splitter, having an input end as connected to an output end of the optical path time regulator, and a second output end connected to the input end of the optical coupler as the second end, such that a part of the seed source optical signals traveling for one cycle within the annular optical cavity are outputted via a first output end of the beam splitter.