Limits...
Developing high energy dissipative soliton fiber lasers at 2 micron.

Huang C, Wang C, Shang W, Yang N, Tang Y, Xu J - Sci Rep (2015)

Bottom Line: Numerical simulation predicts the existence of stable 2 μm dissipative soliton solutions with pulse energy over 10 nJ, comparable to that achieved in the 1 μm and 1.5 μm regimes.Experimental operation confirms the validity of the proposal.These results will advance our understanding of mode-locked fiber lasers at different wavelengths and lay an important step in achieving high energy ultrafast laser pulses from anomalous dispersion gain media.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.

ABSTRACT
While the recent discovered new mode-locking mechanism--dissipative soliton--has successfully improved the pulse energy of 1 μm and 1.5 μm fiber lasers to tens of nanojoules, it is still hard to scale the pulse energy at 2 μm due to the anomalous dispersion of the gain fiber. After analyzing the intracavity pulse dynamics, we propose that the gain fiber should be condensed to short lengths in order to generate high energy pulse at 2 μm. Numerical simulation predicts the existence of stable 2 μm dissipative soliton solutions with pulse energy over 10 nJ, comparable to that achieved in the 1 μm and 1.5 μm regimes. Experimental operation confirms the validity of the proposal. These results will advance our understanding of mode-locked fiber lasers at different wavelengths and lay an important step in achieving high energy ultrafast laser pulses from anomalous dispersion gain media.

No MeSH data available.


Related in: MedlinePlus

(a) Pulse train, (b) laser spectrum, and (c) RF spectrum of the mode-locked Tm-doped fiber laser. The autocorrelation traces of the pulse (d) before and (e) after compression, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4562253&req=5

f5: (a) Pulse train, (b) laser spectrum, and (c) RF spectrum of the mode-locked Tm-doped fiber laser. The autocorrelation traces of the pulse (d) before and (e) after compression, respectively.

Mentions: With the 15 cm GF, the laser reaches its continuous wave (CW) threshold at ~500 mW of pump power. When pump power is increased to ~650 mW, stable CW mode-locking is self-started. Remarkably, no Q-switching or Q-switched mode-locking is observed. This is due to the large output coupling ratio, which suppresses the intermediate transitions between the CW laser operation and the CW mode-locking regime35. The stable CW mode-locked operation maintains when pump power is further increased up to the maximum value. With the maximum available pump power of 1 W, average output power of 158 mW for the 2 μm DS is obtained. Figure 5(a) displays the oscilloscope trace of the mode-locked pulse train at the maximum output, showing a repetition rate of ~32 MHz (corresponding to the round-trip time of ~31 ns). Consequently, the maximum single pulse energy is ~4.9 nJ. The laser spectrum (at the highest output) is analyzed by a mid-infrared spectrum analyzer with a resolution of 0.1 nm, as shown in Fig. 5(b). The wavelength is centered at 1918 nm with a 3-dB spectral width of 15 nm. Steep spectral edges indicate the typical characteristics of DSs1314. The radio-frequency (RF) spectrum has a ~52 dB signal-to-noise ratio (Fig. 5(c)). Figure 5(d) shows the autocorrelation trace of the pulses directly produced from the cavity at the maximum output. Assuming a Gaussian shape, it corresponds to pulse duration of 16 ps. The time-bandwidth product is calculated to be 18, which is a large departure from the Fourier transform limited value. The highly chirped pulse is dechirped to 579 fs (Fig. 5(e)) outside cavity by coupling into a ~25 m SMF-28 fiber. After compression, the time-bandwidth product of the laser pulse is reduced to 0.7.


Developing high energy dissipative soliton fiber lasers at 2 micron.

Huang C, Wang C, Shang W, Yang N, Tang Y, Xu J - Sci Rep (2015)

(a) Pulse train, (b) laser spectrum, and (c) RF spectrum of the mode-locked Tm-doped fiber laser. The autocorrelation traces of the pulse (d) before and (e) after compression, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562253&req=5

f5: (a) Pulse train, (b) laser spectrum, and (c) RF spectrum of the mode-locked Tm-doped fiber laser. The autocorrelation traces of the pulse (d) before and (e) after compression, respectively.
Mentions: With the 15 cm GF, the laser reaches its continuous wave (CW) threshold at ~500 mW of pump power. When pump power is increased to ~650 mW, stable CW mode-locking is self-started. Remarkably, no Q-switching or Q-switched mode-locking is observed. This is due to the large output coupling ratio, which suppresses the intermediate transitions between the CW laser operation and the CW mode-locking regime35. The stable CW mode-locked operation maintains when pump power is further increased up to the maximum value. With the maximum available pump power of 1 W, average output power of 158 mW for the 2 μm DS is obtained. Figure 5(a) displays the oscilloscope trace of the mode-locked pulse train at the maximum output, showing a repetition rate of ~32 MHz (corresponding to the round-trip time of ~31 ns). Consequently, the maximum single pulse energy is ~4.9 nJ. The laser spectrum (at the highest output) is analyzed by a mid-infrared spectrum analyzer with a resolution of 0.1 nm, as shown in Fig. 5(b). The wavelength is centered at 1918 nm with a 3-dB spectral width of 15 nm. Steep spectral edges indicate the typical characteristics of DSs1314. The radio-frequency (RF) spectrum has a ~52 dB signal-to-noise ratio (Fig. 5(c)). Figure 5(d) shows the autocorrelation trace of the pulses directly produced from the cavity at the maximum output. Assuming a Gaussian shape, it corresponds to pulse duration of 16 ps. The time-bandwidth product is calculated to be 18, which is a large departure from the Fourier transform limited value. The highly chirped pulse is dechirped to 579 fs (Fig. 5(e)) outside cavity by coupling into a ~25 m SMF-28 fiber. After compression, the time-bandwidth product of the laser pulse is reduced to 0.7.

Bottom Line: Numerical simulation predicts the existence of stable 2 μm dissipative soliton solutions with pulse energy over 10 nJ, comparable to that achieved in the 1 μm and 1.5 μm regimes.Experimental operation confirms the validity of the proposal.These results will advance our understanding of mode-locked fiber lasers at different wavelengths and lay an important step in achieving high energy ultrafast laser pulses from anomalous dispersion gain media.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.

ABSTRACT
While the recent discovered new mode-locking mechanism--dissipative soliton--has successfully improved the pulse energy of 1 μm and 1.5 μm fiber lasers to tens of nanojoules, it is still hard to scale the pulse energy at 2 μm due to the anomalous dispersion of the gain fiber. After analyzing the intracavity pulse dynamics, we propose that the gain fiber should be condensed to short lengths in order to generate high energy pulse at 2 μm. Numerical simulation predicts the existence of stable 2 μm dissipative soliton solutions with pulse energy over 10 nJ, comparable to that achieved in the 1 μm and 1.5 μm regimes. Experimental operation confirms the validity of the proposal. These results will advance our understanding of mode-locked fiber lasers at different wavelengths and lay an important step in achieving high energy ultrafast laser pulses from anomalous dispersion gain media.

No MeSH data available.


Related in: MedlinePlus