We report on the existence of coherently coupled black-white vector solitons in a net anomalous cavity fiber ring laser. The experimental observation and simulation results provide solid support for the existence evidence.

Shao Guodong;Song Yufeng;Zhao Luming;定元 汤

2016-12-16

We report on large energy pulse generation in an erbium-doped fiber laser passively mode-locked with atomic layer graphene. Stable mode locked pulses with single pulse energy up to 7.3 nJ and pulse width of 415 fs have been directly generated from the laser. Our results show that atomic layer graphene could be a promising saturable absorber for large energy mode locking.

H. Zhang;定元 汤;L. M. Zhao;Q. L. Bao;K. P. Loh

Optics Express

2009-9-28

Highly transparent Er:YAG ceramics with different Er concentration were fabricated by a solid-state reaction and vacuum sintering method. The optical properties, the microstructure and the upconversion luminescence of the Er:YAG ceramics were investigated. For 3 mm thick samples, the in-line transmittances of the as-fabricated Er:YAG ceramics at the wavelength of 1100 nm and 400 nm were about 84% and 82%, respectively, which was very close to the theoretical transmittance of YAG ceramics. The micrograph of the Er:YAG transparent ceramics exhibited a pore-free structure and the average grain size was about 10 μm. The grain boundary of the ceramics was clean and no secondary phase was detected. When pumped by a 980 nm LD, the strong green and red upconversion luminescences in the Er:YAG ceramics were observed. The different upconversion mechanisms depending on Er concentration in the Er:YAG ceramics were also discussed.

Xianpeng Qin;Jian Zhang;Hao Yang;Dewei Luo;Jan Ma;定元 汤;Shiwei Wang

2012

A high-frequency periodic soliton amplitude variation is experimentally observed in a passively mode-locked soliton fiber laser when the modulation instability of the dispersive waves becomes obvious. This experimental result suggested that the influence of the dispersive waves on a soliton is non-negligible when the dispersive waves become unstable. Numerical simulation confirmed the experimental observation. Possible mechanism of soliton-unstable dispersive wave interaction in a laser was elaborated.

B. Zhao;定元 汤;J. Kong;L. M. Zhao;Y. C. Soh

Optics Communications

2005-10-15

We report on the experimental observation of Fermi-Pasta-Ulam (FPU) recurrence in a passively mode-locked fiber ring laser. The spectral sidebands of a CW component generated due to the modulation instability grow up periodically as a result of the reversibility of the effect, demonstrating the existence of FPU recurrence.

B. Zhao;定元 汤;H. Y. Tam

Optics Express

2003-12

Variable optical attenuators (VOAs) have wide applications in DWDM optical communication systems, for example, equalizing the power levers of different wavelength channels, flattening the gain of optical amplifiers, etc. A MEMS variable optical attenuator with fibers connectorized has been developed using proprietary drawbridge structure, which has achieved 1.5 dB insertion loss, 45 dB dynamic range and 37 ms response time, and requires only 8 V driving voltage. Finite element model and analytical model have also been studied and compared with the experimental data, showing that the two models predict the mechanical characteristics of MEMS VOA with reasonable accuracy.

X. M. Zhang;A. Q. Liu;C. Lu;定元 汤;F. Wang;Z. S. Liu;C. Lu

Proceedings of SPIE - The International Society for Optical Engineering

2002

A passively mode-locked soliton fiber-ring laser with 298 fs FWHM pulse width was successfully achieved. The periodic variations of the spectrum width and peak wavelength with the pump power and polarization stability were investigated.

Gong Yandong;Shum Ping;定元 汤

Microwave and Optical Technology Letters

2002-3-5

The formation and features of the cavity solitons in fiber lasers are studied. Due to the cavity induced modulation instability a strong CW beam in a fiber cavity can be automatically switched into a periodic pulse train, and under strong cavity nonlinearity, each of the pulses can be further shaped into a dissipative soliton.

Yufeng Song;Guodong Shao;定元 汤

2015

The room temperature continuous wave (CW) laser performance of a compact Yb:CaYAlO₄ (Yb:CYA) laser with near quantum limit slope efficiency is demonstrated. Pumped with a CW diode operating at 979 nm, the laser emitted a maximum CW output power of 2.3 W at 1050 nm. The corresponding slope efficiency was found to be 92% while the optical to optical conversion efficiency was 70%. The laser can also be continuously tuned from 1008 nm to 1063 nm using an intracavity SF 10 prism. The round trip cavity losses of Yb:CYA was 0.6% while the loss coefficient of the crystal was 0.01 cm^-1.

W. D. Tan;定元 汤;X. D. Xu;D. Z. Li;J. Zhang;C. W. Xu;Z. H. Cong;军 徐

Laser Physics Letters

2011-3

An erbium-doped fiber ring laser is presented. It consists of an inverse-Gaussian apodized fiber Bragg grating acting as a dual-wavelength passband filter, and an unpumped erbium-doped fiber serving as a saturable absorber. The proposed fiber laser can produce two stable lasing lines in which each of them operates in single-longitudinal-mode (SLM). This dual-wavelength SLM laser can generate a microwave signal at 10.502 GHz by beating the dual wavelengths at a photodetector.

Bo Lin;Swee Chuan Tjin;Han Zhang;定元 汤;Sheng Liang;Jianzhong Hao;Bo Dong

2010