title: Second-harmonic generation of an optical frequency comb at 1.55 microm with periodically poled lithium niobate.
abstract: To expand the span of the optical frequency comb (OFC), we generated the second harmonics of an OFC at 1.55microm , using a multiperiod periodically poled lithium niobate (PPLN) crystal. A coupled-cavity OFC generator with an average output power of 0.2 mW was amplified and expanded with a fiber amplifier and a dispersion-flattened fiber. The fundamental OFC average power and span were 100 mW and 45 THz, respectively. The second-harmonic comb's span was 3.2 THz; however, we tuned the center frequency over 30 THz by changing the poling period. We also demonstrated that the second-harmonic comb can be used for frequency-difference measurement.
authors: B
authors: B
authors: Widiyatmoko
authors: K
authors: K
authors: Imai
authors: M
authors: M
authors: Kourogi
authors: M
authors: M
authors: Ohtsu