Tunable Ho-doped soliton fiber laser mode-locked by carbon nanotube saturable absorber

Abstract

We demonstrate sub-picosecond holmium-doped fiber laser mode-locked with a broadband carbon nanotube saturable absorber. Ultrashort pulse operation has been obtained for the wavelength range of 2030 -2100 nm with output power up to 60 mW and repetition rate of 15.7 MHz.

Carbon nanotubes for ultrafast fibre lasers

“…An analogous approach has been demonstrated in [65], though the cavity comprised of pure Ho-doped fibre. The shortest achieved pulse duration was 890 fs at 2085 nm, with an average output power of 45 mW.…”

“…By adjustment of the polarisation controller and scanning the modal spot over the CNT reflector, optical pulse spectra could be tuned in the range of 2030-2100 nm ( Figure 19). The other method to realise the wide spectral tenability involved the intentional variation of CNT film thickness across the sample, resulting in a spectral shift of CNT absorption [65]. …”

“…There are numerous reports in the literature [50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67] on the use of SWNTs as mode lockers and Q-switches for ultrafast lasers in the broad wavelength band, which are summarised in Table 1. One of the main advantages of SWNT-based SAs, apart from ultrashort relaxation time and high nonlinearity, is the ease of their fabrication and implementation into the laser setup.…”

All-Fiber, Wavelength and Repetition-Rate Tunable, Ultrafast Pulse Generation in the 2.0 μm Region Without Mode-Locking

“…Fiber platforms show the most promise for simple and cost-effective pulse generation at 2.0 μm and there have been two main approaches: 1) direct pulse generation using passive mode-locking in thulium (Tm), holmium (Ho), or TmHo codoped fiber [8]- [11] and 2) indirect pulse generation using nonlinear frequency conversion of pulses derived from lowerwavelength fiber oscillators [12]- [14]. Recent approaches using direct pulse generation have shown wavelength tuning of up to 70 nm [8], [10] which is impressive for these systems, but small compared to nonlinear frequency conversion. Pulse generation using the latter method has shown wavelength-tuning more than 500 nm, but at the cost of high-energy seed sources and amplifiers.…”

Low noise, tunable Ho:fiber soliton oscillator for Ho:YLF amplifier seeding

“…The transition between the 5 I 7 and 5 I 8 manifolds exhibits a large emission cross-section and a gain bandwidth suitable for the amplification of fs-pulses, which allows the direct generation of pulse-trains within the amplifer gain spectrum with variable parameters. However, most previously demonstrated Ho:fiber and solid state oscillators did not meet the spectral requirements for subsequent amplification [24][25][26].…”