We theoretically analyze and experimentally demonstrate a method of generating equal-amplitude optical comb exploiting multi-frequency phase modulation. The theoretical analysis shows that 4n-1 equal amplitude spectral lines can be obtained when the modulation signal comprises n frequency components including the fundamental frequency and the odd harmonic frequencies, and 2n+1 equal-amplitude spectral lines can be obtained when the modulation signal comprises n frequency components including the fundamental frequency and the even harmonic frequencies. Then, we numerically simulate the spectra of 5, 7, 9, and 11 equal-amplitude spectral lines, respectively, which are also obtained in experiments with frequency separation of 30 MHz and flatness of better than 0.3 dB.
© 2010 Chinese Optics Letters
Yuelan Lu, Yongwei Xing, and Yongkang Dong, "Equal-amplitude optical comb generation using multi-frequency phase modulation in optical fibers," Chin. Opt. Lett. 8, 316-319 (2010)