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Gold nanorod saturable absorber for passive mode-locking at 1 μm wavelength

Gold nanorods (GNRs) were used as a saturable absorber (SA) for passive mode-locking at 1 μm wavelength. The GNR-SA film was fabricated by mixing GNRs with sodium carboxymethylcellulose. The longitudinal surface plasmon resonance absorption of GNRs was used to induce mode-locking. By using the GNR-SA film, stable passive mode-locking at 1039 nm was experimentally demonstrated in an ytterbium-doped fiber laser cavity pumped by a 980 nm laser diode. The laser produced ~440 ps pulses with a repetition rate of 36.6 MHz and an average output power of ~1.25 mW for a pump power of ~82 mW.

Mode-locked thulium-doped fiber laser at 1982 nm by using a gold nanorods saturable absorber

We demonstrated a passively mode-locked fiber laser operating at 1982 nm by using a gold nanorods (GNRs) saturable absorber (SA). The GNRs SA was fabricated by mixing GNRs with sodium carbonxymethyl cellulose. By inserting the GNRs SA into a Tm-doped fiber laser cavity pumped by a 1570 nm fiber laser, stable passively mode-locking was achieved with a threshold pump power of 224 mW, ~4.02 ps pulses at 1982 nm with a repetition rate of ~37.49 MHz, and a maximum average power of ~6 mW was obtained for a pump power of ~265 mW.

All-fiber widely tunable mode-locked thulium-doped laser using a curvature multimode interference filter

We demonstrated a widely tunable mode-locked thulium doped fiber laser (TDFL) by using a homemade multimode interference filter (MMIF). The MMIF had a structure of single mode fiber (SMF)-multimode fiber (MMF)-SMF and three main transmission peaks at 1901.2, 1957.2 and 2043.2 nm. By mechanically bending the MMIF, the three main transmission peaks were tuned in the range of 1860-2024 nm due to multimode interference effect. By inserting the MMIF into a passively mode-locked TDFL cavity pumped by a 1570 nm fiber laser, a tunable mode-locked TDFL with a tuning range of 1919.6-2014.9 nm was achieved by adjusting the MMIF. To the best of our knowledge, such a tunable range is the largest among all-fiber tunable mode-locked TDFLs.

Supercontinuum generation from 437 to 2850 nm in a tapered fluorotellurite microstructured fiber

We demonstrated supercontinuum (SC) generation in a tapered fluorotellurite microstructured fiber (MF) with a sub-micrometer core diameter. Fluorotellurite MFs based on TeO2–BaF2–Y2O3 glasses were fabricated by using a rod-in-tube method and a tapered fluorotellurite MF with a minimum core diameter of ~0.65 µm was prepared by employing a tapering system. A 1560 nm femtosecond fiber laser was used as the pumping source. With increasing the peak power of the launched pump laser to ~11 kW, SC light expanding from 437 to 2850 nm was generated in the tapered fluorotellurite MF. In addition, relatively strong blue-shifted dispersive wave at ~489 nm was also observed from the tapered fluorotellurite MF.

0.8 nm single wall carbon nanotubes for wideband ultrafast pulse generation

We demonstrate wideband ultrafast optical pulse generation at 1, 1.56 and 2 μm by using single polymer composite saturable absorber (SA) based on 0.8 nm single wall carbon nanotubes (SWCNTs). The SWCNTs were mixed with sodium carboxymethylcellulose (NaCMC) to form SWCNT SA films. The film then integrated into ytterbium-(Yb-), erbium-(Er-) and thulium-(Tm-) doped ring fiber laser cavities. Using this film, we achieve 380 ps, 830 fs, and 1.24 ps mode-locked pulses at 1035, 1560, and 1933 nm, respectively. These results suggest that 0.8 nm SWCNTs are potentially useful as optical elements in wideband fiber lasers.