Dynamics of an ultrahigh-repetition-rate passively mode-locked Raman fiber laser

Nonlinear optical signal processing in high figure of merit CMOS compatible platforms

“…Figure 6 shows the device configuration of the RF spectrum analyzer while Figure 7 shows its measured frequency response showing a 3dB bandwidth of about 2.6THz, limited by our system measurement capability. We believe the intrinsic bandwidth is substantially higher than this since the simple theoretical prediction used in [52,53] yields a bandwidth more than 100THz. In practice this would likely be limited by higher order dispersion, mode cutoff and even absorption bands, since the simple model of [56,57] does not include these effects.…”

“…Although dissipative FWM yielded transform limited pulses at very high repetition rates, a fundamental problem is super-mode instability where multiple pulses circulate in a cavity. This is a consequence of the much smaller cavity mode frequency spacing of a few megahertz or less, which allows many modes to oscillate within the Fabry Pérot filter bandwidth, thus producing extremely unstable operation [52]. Figure 2 shows the configuration of the first modelocked laser [21,23] based on a nonlinear monolithic high-Q resonator that achieved extremely stable operation at high repetition rates while maintaining very narrow linewidths.…”

High-harmonic km-long self-pulsed Raman fiber laser

“…Still, little is known about their potential as pulsed laser sources. Mode locked Raman fiber lasers have been demonstrated quite recently [1,2], as well as harmonic mode-locking with a record of 500,000 intra-cavity pulses in a dissipative four-wave mixing configuration using a fiber Bragg grating [3]. Here we demonstrate experimentally the generation of high harmonics through the combination of nonlinear polarization evolution and Raman amplification in a dispersion-shifted fiber (DSF) cavity.…”

193-GHz 53-W Subpicosecond Pulse Source

“…Ultrafast microchip solid state lasers are capable of watt-level output powers with excellent beam quality, but their repetition rate has so far been limited below 160 GHz by the gain bandwidth of the used gain crystals [8]. For fiber lasers with repetition rates above 100 GHz, supermode noise limits temporal stability and pulse quality due to operation at extremely high harmonic frequencies of the typically rather low cavity resonance frequency [9], [10]. Stable pulse trains at hundreds of gigahertz repetition rates can be obtained via four-wave mixing in high quality factor microring resonators that eliminate the need of long cavities for efficient nonlinear interaction and circumvent the stability issues present in four-wave mixing schemes with fibers [11].…”