Single-walled Carbon Nanotube Absorber Research Articles

All-fiber dissipative soliton laser based on single-walled carbon nanotube absorber in normal dispersion regime

We demonstrat a compact Yb-doped fiber (YDF) laser based on the single-walled carbon nanotube (SWCNT) wall-paper absorber. It can operate at dissipative solitons mode-locking state stably for more than 24h at the room temperature, and there is no significant degradation of the laser spectra, pulse train, and output power. The spectral bandwidth of the mode-locked pulses varies from 0.35 to 0.64nm depending on the level of the pump power. The amplified pulses possess single pulse energy of 3.87nJ and pulse duration of 421.9ps. The repetition rate is ∼23.83MHz. The largest output power reaches 92.3mW.

Polydopamine Coated Single-Walled Carbon Nanotubes as a Versatile Platform with Radionuclide Labeling for Multimodal Tumor Imaging and Therapy.

Single-walled carbon nanotubes (SWNTs) with various unique properties have attracted great attention in cancer theranostics. Herein, SWNTs are coated with a shell of polydopamine (PDA), which is further modified by polyethylene glycol (PEG). The PDA shell in the obtained SWNT@PDA-PEG could chelate Mn2+, which together with metallic nanoparticulate impurities anchored on SWNTs offer enhanced both T1 and T2 contrasts under magnetic resonance (MR) imaging. Meanwhile, also utilizing the PDA shell, radionuclide 131I could be easily labeled onto SWNT@PDA-PEG, enabling nuclear imaging and radioisotope cancer therapy. As revealed by MR & gamma imaging, efficient tumor accumulation of SWNT@PDA-131I-PEG is observed after systemic administration into mice. By further utilizing the strong near-infarared (NIR) absorbance of SWNTs, NIR-triggered photothermal therapy in combination with 131I-based radioisotope therapy is realized in our animal experiments, in which a remarkable synergistic antitumor therapeutic effect is observed compared to monotherapies. Our work not only presents a new type of theranostic nanoplatform based on SWNTs, but also suggests the promise of PDA coating as a general approach to modify nano-agents and endow them with highly integrated functionalities.

Ultrafast laser performance of Yb 3 + : Sc 2SiO 5 crystal with a single-walled carbon nanotube absorber

Single-walled carbon nanotube (SWCNT) absorber fabricated by vertical evaporation is used in passively mode-locked Yb 3 + :Sc 2SiO 5 (Yb:SSO) ultrafast laser for the first time. The performance of Yb:SSO ultrafast laser with pulse width as short as 880 fs is studied and the average output power is 712 mW. To our knowledge, this is the highest output power of femtosecond lasers with SWCNT-SAs reported. In addition, we firstly demonstrate a passively mode-locked picosecond Yb:SSO laser without inserting any dispersion compensation device. The pulses width is as short as 5.4 ps and the output power is 940 mW.

Errata: Efficient diode-pumped Yb:LuYSiO<sub>5</sub> laser mode locked by single-walled carbon nanotube absorber

Efficient diode-pumped Yb:LuY2SiO5 laser mode locked by single walled carbon nanotube saturable absorber is reported for the first time. Under the absorbed pump power of 12.83 W, continuous wave mode-locked pulses were generated with the maximum average output power of 1.50 W. We obtained pulses as short as 5.2 ps around a center wavelength of 1058.6 nm. The peak power and the single pulse energy of the mode-locked laser were up to 2.9 kW and 15.0 nJ, respectively.

2 μm passive Q-switched mode-locked Tm 3+:YAP laser with single-walled carbon nanotube absorber

We report the first demonstration, to our knowledge, of passive Q-switched mode-locking in a Tm 3+:YAP laser, operating in the 2 μm broadly spectral region formed with a compact Z-flod cavity. A transmission-type single-walled carbon nanotube saturable absorber (SWCNT–SA) is used for the initiation of the pulse generation. The repetition rate of the Q-switched envelope was 60 kHz at the pump power of 8.6 W. The mode-locked pulses inside the Q-switched pulse envelope had a repetition rate of ∼92 MHz. A maximum average output power of 761 mW was obtained. The dependence of the operational parameters on the pump power was also investigated experimentally.

Efficient diode-pumped Yb:LuYSiO<sub>5</sub> laser mode locked by single-walled carbon nanotube absorber

Efficient diode-pumped Yb:LuY2SiO5 laser mode locked by single walled carbon nanotube saturable absorber is reported for the first time. Under the absorbed pump power of 12.83 W, continuous wave mode-locked pulses were generated with the maximum average output power of 1.50 W. We obtained pulses as short as 5.2 ps around a center wavelength of 1058.6 nm. The peak power and the single pulse energy of the mode-locked laser were up to 2.9 kW and 15.0 nJ, respectively.

Carbon nanotubes as multifunctional biological transporters and near-infrared agents for selective cancer cell destruction

Biological systems are known to be highly transparent to 700- to 1,100-nm near-infrared (NIR) light. It is shown here that the strong optical absorbance of single-walled carbon nanotubes (SWNTs) in this special spectral window, an intrinsic property of SWNTs, can be used for optical stimulation of nanotubes inside living cells to afford multifunctional nanotube biological transporters. For oligonucleotides transported inside living cells by nanotubes, the oligos can translocate into cell nucleus upon endosomal rupture triggered by NIR laser pulses. Continuous NIR radiation can cause cell death because of excessive local heating of SWNT in vitro. Selective cancer cell destruction can be achieved by functionalization of SWNT with a folate moiety, selective internalization of SWNTs inside cells labeled with folate receptor tumor markers, and NIR-triggered cell death, without harming receptor-free normal cells. Thus, the transporting capabilities of carbon nanotubes combined with suitable functionalization chemistry and their intrinsic optical properties can lead to new classes of novel nanomaterials for drug delivery and cancer therapy.

Near-Infrared Absorbance of Single-Walled Carbon Nanotubes Dispersed in Dimethylformamide

Absorption spectra of single-walled carbon nanotubes (SWNT) dispersed in dimethylformamide (DMF) have been recorded in the visible to near-infrared range. Besides broad absorption bands, the spectra show a sharp peak at 5187 cm-1, which has been attributed in the literature to the absorption of semiconducting nanotubes with a band gap of 0.64 eV [Ausman et al. J. Phys. Chem. B 2000, 104, 8911]. On the basis of absorbance measurements for samples that show the sharp absorbance peak but do not contain SWNTs, we conclude that the origin of the peak at 5187 cm-1 is not due to semiconducting nanotubes but due to water present in the SWNT/DMF suspension. A comparative study of D2O in DMF reproduces a similar peak that is isotope-shifted into the near-infrared.