Octave-Spanning Fiber Laser Comb with 300 MHz Comb Spacing for Optical Frequency Metrology

Direct Generation of 148 nm and 44.6 fs Pulses in an Erbium-Doped Fiber Laser

“…Ultrashort pulse fiber lasers with repetition rates higher than 200 MHz are attractive in numerous applications, such as frequency comb generation for optical frequency metrology [1]- [4], arbitrary optical waveform generation [5], high-speed optical sampling [6]- [8]. Active mode-locking technique and harmonically passive mode-locking technique have been adopted to generate pulse trains with high repetition rates.…”

“…Furthermore, NPE based passive mode-locked fiber lasers often exhibit excellent noise characteristics and thereby low timing jitter in long-term stable operation [20], [21]. To date, the fiber lasers adopting this cavity configuration can achieve high fundamental repetition rates of more than 200 MHz [3], [4], [22]- [24]. However, there is still one issue to be solved.…”

“…However, there is still one issue to be solved. The output optical spectra are relatively narrow in most lasers [3], [4], [22], [23]. Although the optical spectrum broader than 135 nm was reported, it is still non-flat since several irregular concavities appear [24].…”

Octave-spanning frequency comb generated by 250 fs pulse train emitted from 25 GHz externally phase-modulated laser diode for carrier-envelope-offset-locking

“…However, the modes of the current CEO-locked frequency combs are still too densely spaced to be spectrally resolved in a simple manner and are thus not accessible for individual use. Up to now, the reported widest mode spacing of a CEO-locked frequency comb in the 1.5 mm band is 300 MHz [2]. Expanding the mode spacing requires optical sources with a higher repetition rate.…”

Periodically poled lithium niobate ridge waveguides with high conversion efficiency for 2 f ‐to‐3 f self‐referencing interferometer

“…Introduction: A carrier-envelope-offset (CEO)-locked frequency comb with wide mode spacing (> 10 GHz) could be applied to future photonic networks, astronomical spectroscopy [1], and line-by-line optical pulse shaping [2]. The reported widest mode spacing of a CEO-locked frequency comb in the 1.5 µm band is 300 MHz [3], which is still too densely spaced to be spectrally resolved in a simple manner and thus not accessible for individual use. In addition, since laser sources with more than 10 GHz repetition rates typically have relatively long pulse durations and reduced pulse energy, it is difficult to generate octavesupercontinuum (SC) spectra as required for detecting a CEO frequency ( f 0 ) in a conventional f-to-2f self-referencing interferometer (SRI).…”