Research On The Generation And Applications Of Optical Frequency Comb Based On Laser External Modulation

Optical frequency comb (OFC) is an optical source with comb spectrum. It has importantapplications in high precision frequency standard, precision ranging，arbitrary wave generated inmicrowave photonics (MWP), signal procession in MWP and DWDM. Optical clock based on OFCcan improve the precision of atomic clock more than2orders. As the meaning in theory andapplications, OFC has become a research hot spot in related areas.The paper studies the generation and application of OFC from the point of MWP. Firstly, thestatus and the major principle of OFC have been introduced. Secondly, two generating precepts basedon laser external modulated have been raised and experiment verified. Finally, used the OFC thatgenerated through the proposed scheme, a precept that broads the measuring range based on singleside band vector network analyzer has been put forward. And an experiment has been done, provingthe practicable of the scheme. The major contents conclude that: the author proposed a scheme thatgenerated an ultra-flat optical frequency comb based on cascaded polarization modulators. Throughanalyzing the principle, a related parameter that satisfied the equation has been calculated. And asimulation has also been done. Then, a related experiment has been done to verify the scheme. AnOFC with25comb lines, ranged from3.5GHz to5GHz, with the flatness less than1dB and keepingstable in an hour has been generated. Another scheme is which generates a flat optical frequencycomb based on a polarization modulator and a phase modulator. Through analyzed the principle, arelated parameter that satisfied the equation has been calculated. And a simulation has also been done.Then, a related experiment has been done to verify the scheme. An OFC used small RF power with13variable comb lines. And through simulation,19comb lines with flatness less than1.65dB can begenerated. A study in optical measurement based on OFC has been done. And a scheme that broadsthe measuring range based on single side band vector network analyzer has been put forward.Through analyzing the principle, an experiment has been done proving the correction of the scheme. Aresult that can broad the measure range more than5times with the accuracy of measurement1MHzand measure bandwidth105GHz has obtained.