A passively mode locked fiber soliton laser was experimentally configured. A pigtailed InGaAsP laser diode operating at 1480 nm was used to pump the laser, and the maximum output power was 140 mW. Unidirectional operation of the laser was enforced by the inclusion of a polarization-dependent isolator in the cavity. Bound soliton pulses with FWHM width of 326 fs and fixed separation of 938 fs were achieved, with existence of a strong continuous wave component at the center of soliton spectrum.

Gong Yandong;Shum Ping;定元 汤;Cheng Tee Hiang

2002

Properties of the glasses are experimentally investigated when Ga is gradually substituted by Ge in Ga₈Sb₃₂S₆₀ chalcogenide glass. The glass structure is also studied to elucidate the variations of the properties. While the substitution of Ga by Ge does not remarkably change the glass transition temperature T_g, the thermal stability against crystallization becomes optimum when half of the Ga atoms are replaced by Ge atoms. The short-wavelength absorption edge λ_S (or optical bandgap E_g) exhibits a remarkable decrease when a small amount of Ge is added, however, its value does not change significantly with further Ga substitution. As Ga is gradually replaced by Ge, the long-wavelength cut-off edge λ_L, the density ρ, the linear refractive index n, and the third-order nonlinear refractive index n₂ decrease. It is shown that the property variations of the glasses could be explained by the evolution of the glass structure.

Mingjie Zhang;Zhiyong Yang;Lei Li;Yuwei Wang;Jiahua Qiu;Anping Yang;海征 陶;定元 汤

Journal of Non-Crystalline Solids

2016-11-15

We report on the experimental observation of a new type of polarization-locked vector soliton in a passively mode-locked fiber laser. The vector soliton is characterized by the fact that not only are the two orthogonally polarized soliton components phase-locked, but also one of the components has a double-humped intensity profile. Multiple phase-locked high-order vector solitons with identical soliton parameters and harmonic mode locking of the vector solitons were also obtained in the laser. Numerical simulations confirmed the existence of stable high-order vector solitons in the fiber laser.

定元 汤;H. Zhang;L. M. Zhao;X. Wu

Physical Review Letters

2008-10-10

1.6 μm eye-safe emission of a diode pumped Er,Yb co-doped YAG ceramic laser is firstly demonstrated. Operation of the ceramic laser under different ceramic sample lengths, co-doping concentrations and control temperatures were experimentally investigated. A maximum output power of 222 mW was achieved at an absorbed pump power of 8.1 W, corresponding to a conversion efficiency of 2.74%. Laser emission at 1.05 μm for transition of the Yb³⁺ ions was also studied on the same ceramic samples. The results clearly show the existence of resonantly energy transfer from the Yb³⁺ ions to Er ³⁺ ions.

Haiyong Zhu;定元 汤;Yanmin Duan;Dewei Luo;Jian Zhang

Optics Express

2013-11-4

Using two 20 mm in diameter, 1.4 mm thick, 5 at% doping Yb:YAG ceramic active elements (AEs) we reached 233 mJ at 143 Hz in the output with 70 ns, 30 mJ input pulses. According to our 3D calculations we extracted about half of the stored energy. To our knowledge, this output result is the best among all high repetition rate cryogenic pulse Yb:YAG ceramic thin disk laser systems.

Evgeny Perevezentsev;Ivan Mukhin;Olga Vadimova;Oleg Palashov;Efim Khazanov;Dewei Luo;Jian Zhang;定元 汤

Physica Status Solidi (A) Applications and Materials Science

2013-6

We study a mechanism to attain stable and ultra-flat multiwavelength oscillations in erbium-doped fiber lasers (EDFLs). The key concept is to introduce intensity-dependent loss (IDL) into the laser cavity, which can effectively suppress the mode competition in the homogeneously broadened gain medium and ensure a uniform power distribution over wavelengths via the gain-clamping effect. The technique was successfully demonstrated by employing a nonlinear optical loop mirror (NOLM) in erbium-doped fiber laser cavity. Based on the experimental results, further experimental investigation and theoretical analysis are carried out to show the effectiveness of the gain-clamping mechanism in realizing the multiwavelength operation of the EDFL.

新焕 冯;C. Lu;H. Y. Tam;P. K.A. Wai;定元 汤;Bai Ou Guan

Optics and Laser Technology

2012-2

Summary form only given. It is shown that the focusing laser intensity is incompatible with the effective gain length in general stimulated Raman scattering (SRS) experiments. To explore the potential effect of the nonlinear medium under high intensity and long gain length, a special liquid waveguide system that can offer a gain length of more than 10 m was designed.

Guangsheng He;定元 汤;Zhouliang Cao;Fuxin Zhou;Runwen Wang;Songhao Liu

1985

We report on the first experimental observation of bound states of vector dissipative solitons (VDSs) in an erbium-doped fiber laser mode locked with a semiconductor saturable absorber mirror and operated in the normal dispersion regime. Bound states of either the coherently coupled VDSs or the incoherently coupled VDSs were obtained. No polarization evolution was observed for either of the bound VDSs. Both types of bound VDSs have a fixed soliton separation, which is invariant to the laser operation condition. Numerical simulations confirm the experimental observations.

L. M. Zhao;定元 汤;H. Zhang;X. Wu

IEEE Photonics Journal

2015-12-1

Gain-guided solitons are experimentally observed in dispersion-managed fiber lasers with large net positive group-velocity dispersion. It is shown that formation of the soliton is a robust feature of the lasers. Numerical simulations also confirmed the experimental results.

L. M. Zhao;定元 汤;T. H. Cheng;C. Lu

Optics Letters

2006-10-15

We report on a compact high-power passively mode-locked Nd:LuVO₄ laser by use of semiconductor saturable absorber mirror (SESAM). The laser generated clean CW mode-locked pulses with an average output power of 8.6 W, a repetition rate of 144 MHz, and a pulse duration of 13.2 ps. By employing a three-mirror cavity scheme, the laser setup has only a footprint size of 70× 30 cm², which can be packaged to a portable laser system for convenient applications. A graph is presented. Average output power vs. absorbed pump power.

G. Q. Xie;定元 汤;H. Luo;H. H. Yu;怀金 张;列加 钱

Laser Physics Letters

2008-9