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摘要：
Generation of ultrashort, transform-limited pulses in a laser resonator by means of nonlinear pulse amplification and compression is observed both numerically and experimentally; this constitutes another type of pulse shaping mechanism in the mode-locked lasers. It is shown that as a result of nonlinear pulse compression, mode-locked pulse with pulse width beyond the gain bandwidth limitation could be directly generated in a laser.
作者：
L. M. Zhao;定元汤;T. H. Cheng;C. Lu
刊名：
Applied Physics Letters
在线出版时间：
2007

摘要：
Gain-guided solitons are experimentally observed in dispersion-managed fiber lasers with net positive group velocity dispersion. In contrast to the conventional solitons generated in fiber lasers with net negative dispersion, gain-guided solitons have steep spectral edge(s), large pulse width and broader bandwidth, which are also different to the dispersion-managed solitons generated in fiber lasers with net positive but near zero dispersion.
作者：
L. M. Zhao;定元汤;T. H. Cheng;C. Lu
刊名：
在线出版时间：
2006

摘要：
The photoluminescence (PL) of multiwalled carbon nanotubes (MWCNTs) synthesized with ethanol flames was investigated at temperatures from 30 to 300 K. Broad-band PL emission in the near-infrared region was observed at temperatures below 240 K. The PL intensity was abruptly boosted up at 240 K, and then quickly became quenched and undetectable as the temperature was further increased. The PL emission of the MWCNTs only appeared in the first cycle of the temperature rising. However, it could be recovered by exposing the sample in an oxygen-abundant environment. We propose that the PL emission of the MWCNTs is resulted from the carbon oxyhydride-like fluorophors bound to the MWCNTs surface.
作者：
Qiaoliang Bao;Jun Zhang;春旭潘;Jun Li;Chang Ming Li;剑锋臧;定元汤
刊名：
Journal of Physical Chemistry C
在线出版时间：
2007-7-19

摘要：
Pulse breaking recovery is numerically demonstrated in dispersion-managed fiber lasers designed for generating high peak power ultrashort optical pulses. It is shown that due to the cavity boundary condition, local pulse breaking can be absorbed by the pulse propagation in erbium-doped fiber with normal dispersion. Consequently, high peak power transform-limited pulses beyond the gain-bandwidth limitation could be generated.
作者：
L. M. Zhao;定元汤;H. Y. Tam;C. Lu
刊名：
Optics Express
在线出版时间：
2008-8-4

摘要：
A fiber Bragg grating (FBG) with an inverse-Gaussian apodization function is proposed and fabricated. It is shown that such a FBG possesses dual-wavelength narrow transmission peaks and the wavelength spacing between the two peaks is easily controllable during fabrication. Incorporating such a FBG filter into a fiber laser with a linear cavity, we obtain stable dual-wavelength emission with 0.146 nm wavelength spacing. This arrangement provides a simple and low cost way of achieving dual-wavelength fiber laser operation.
作者：
Bo Lin;Han Zhang;Swee Chuan Tjin;定元汤;Jianzhong Hao;Chia Meng Tay;Sheng Liang
刊名：
Applied Optics
在线出版时间：
2010-3-10

摘要：
Based on the Maxwell-Bloch formalism, operation of a passively mode-locked fiber laser is numerically investigated. It is found that even without the Ginzburg-Landau Equation (GLE) approximation stable solitary waves can still be obtained in the laser due to the cavity pulse peak clamping effect. We further show that the effects of coherence play a significant role in determining the parameters of the formed solitary pulses.
作者：
D. J. Lei;定元汤;L. M. Zhao;双春文;喜泉傅;H. W. Xu
刊名：
在线出版时间：
2007

摘要：
Passively cw mode-locked laser operation of Yb-doped NaY (WO₄)₂ (Yb:NaYW) crystal was demonstrated with an average power of 400 mW. This is the highest power achieved from the mode-locked Yb:NaYW laser to our knowledge. The laser was end-pumped by a high power fiber pigtailed laser diode bar and the mode-locking was enabled by a semiconductor saturable absorber mirror (SESAM). The laser pulse duration was 1.1 ps, centered at the wavelength of 1019.7 nm with a band-width of 1.6 nm, and nearly transform-limited. A figure is presented. Pulse trains of (a) cw mode-locking and (b) Q-switched mode-locking from Yb:NaYW laser output.
作者：
Hang Luo;定元汤;G. Q. Xie;怀金张;L. J. Qin;H. H. Yu;列加钱
刊名：
Laser Physics Letters
在线出版时间：
2008-9

摘要：
Tunable lasers have wide applications in DWDM systems to save inventory cost and to improve the optical network functionalities. The Microelectromechanical Systems (MEMS) technology has shown strong promise to miniaturize the conventional mechanical tunable lasers with adding merits of high compactness, high speed, batch production and so on. In this paper, external cavity tunable diode lasers using MEMS movable mirrors and rotary gratings as the external reflectors are presented. One tunable laser of 2 mm × 1.5 mm is formed by integration of a surface-micromachined 3D mirror with a diode laser and an optical fiber. In addition, deep-etched structures such rotary gratings, circular mirror, microlens, and grooves for diode laser and fiber are illustrated to form widely tunable lasers.
作者：
X. M. Zhang;J. Li;定元汤;C. Lu;A. Q. Liu
刊名：
Proceedings of SPIE - The International Society for Optical Engineering
在线出版时间：
2003

摘要：
We show both numerically and experimentally that a dissipative type of Akhmediev-breathers (ABs) and Peregrine solitons (PSs) can be formed in a fiber laser, and their features could be well described by the laser Ginzburg-Landau equation. Moreover, we show that laser gain bandwidth limitation effect can arrest the dissipative ABs. Consequently, a stable one-dimensional periodic pulse train or periodic PS crystal structure can be formed. A kind of movable ‘PSs’ has also been obtained in our fiber laser. The solitons have a PS-like profile but exhibit similar features as those of the dissipative solitons formed in a mode locked fiber laser.
作者：
X. Hu;J. Guo;Y. F. Song;L. M. Zhao;L. Li;定元汤
刊名：
JPhys Photonics
在线出版时间：
2020-7-6

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