Shenghong Huang

589 nm Light Source Based on Raman Fiber Laser

A fiber-based continuous-wave laser at 589 nm was demonstrated by intracavity frequency doubling of a Raman fiber laser at 1178 nm in a type-I noncritically phase matched lithium triborate crystal. The yellow laser output was limited by the emergence of higher order Stokes Raman emission and the broad linewidth of the fundamental laser at 1178 nm.

Multiple-color cw visible lasers by frequency sum-mixing in a cascading Raman fiber laser

Multiple cw visible lasers at wavelengths ranging from 550nm to 625nm were generated by intracavity frequency sum-mixing of a cascading Raman fiber laser in a type-I noncritically phase-matched lithium triborate crystal. The phase matching conditions for individual wavelengths were realized by tuning the temperature of the lithium triborate crystal.

Thermal effects in quasi-continuous-wave Nd3+:Y3Al5O12 nanocrystalline-powder random laser

We report an experimental investigation on the thermal effects in a Nd3+:Y3Al5O12 nanocrystalline-powder random laser with a one-mirror structure by quasi-continuous-wave laser diode pumping. Extremely low thermal conductivity in powder and significant temperature dependence of the narrow emission spectrum of Nd3+:Y3Al5O12 leads to a laser line redshift and gain reduction with a higher heat deposit. Mode drifting induced by the temperature dependence of the refractive index is also discussed.

784-nm amplified spontaneous emission from Tm 3+ -doped fluoride glass fiber pumped by an 1120-nm fiber laser

We report 784-nm (1G4 --> 3H5 transition) amplified spontaneous emission (ASE) from Tm3+-doped fluoride (ZrF4-BaF2-LaF3-AlF3-NaF) glass fiber pumped by an 1120-nm fiber laser. To our best knowledge, this is the first report of 784-nm (1G4 --> 3H5 transition) ASE in a Tm3+-doped fluoride fiber laser. Its effects on a 480-nm (1G4 --> 3H6 transition) blue laser were also discussed.

Generation of 10.5 W, 1178 nm Laser Based on Phosphosilicate Raman Fiber Laser

The phosphorous-doped Raman fiber laser fabricated based on a Fabry-Perot cavity is demonstrated. The fiber length (L) values of 300 m and 700 m, and the reflectivity (R) values of the output fiber Bragg grating (FBG) of 15%, 30% and 50% are adopted. Under the optimum configuration of L=300 m, and R=15%, a 10.5 W, 1178 nm laser is obtained. Considering the pump power of 19.2 W, the optical-optical conversion efficiency is 54.7% and the corresponding slope efficiency is 80%. The 1178 nm light is frequency-doubled to generate 589 nm light as a source for the laser guide star (LGS) for the mesospheric sodium layer.

Single-frequency fiber laser from linear cavity with loop mirror filter and dual-cascaded FBGs

A single-frequency ytterbium fiber laser was demonstrated by introducing a loop mirror filter, a polarization controller (PC), and dual-cascaded fiber Bragg gratings (FBGs) in linear laser cavity. The loop mirror with unpumped ytterbium fiber as a narrow bandwidth filter discriminated and selected laser longitudinal modes efficiently. The spatial hole burning effect was restrained by adjusting PC appropriately. Dual closely cascaded FBGs as the output coupler, acting as an etalon, expanded the operation range of single frequency. Output power up to 18 mW at 1064 nm were obtained under the launched pump power of 107 mW at 976 nm, the optical-optical conversion efficiency was about 16.8%; the slope efficiency was about 20%.

Multiple-wavelength up-conversion laser in Tm/sup 3+/-doped ZBLAN glass fiber

In this letter, we report on a multiple-wavelength up-conversion laser in Tm/sup 3+/-doped ZrF/sub 4/--BaF/sub 2/--LaF/sub 3/--AlF/sub 3/--NaF glass fiber pumped by an 1120-nm fiber laser. Single-wavelength, two-wavelength, and three-wavelength up-conversion lasers can be obtained by adjusting the distance between the coupler mirror and the fiber end, which is attributed to the frequency-filter effect in the etalon composed of the coupler mirror and the fiber end. The effects of the pump power on the performance of dual-wavelength laser were also discussed.

Single frequency 1083nm ytterbium doped fiber master oscillator power amplifier laser.

Single frequency 1083nm ytterbium fiber master oscillator power amplifier system was demonstrated. The oscillator was a linear fiber cavity with loop mirror filter and polarization controller. The loop mirror with unpumped ytterbium fiber as a narrow bandwidth filter discriminated and selected laser longitudinal modes efficiently. Spatial hole burning effect was restrained by adjusting polarization controller appropriately in the linear cavity. The amplifier was 5 m ytterbium doped fiber pumped by 976nm pigtail coupled laser diode. The linewidth of the single frequency laser was about 2 KHz. Output power up to 177 mW was produced under the launched pump power of 332 mW.

Random microchip laser

A microchip-type laser with multiple scattering from powder as necessary feedback is demonstrated. The laser consists of a transparent ceramic Nd:YAG microchip and a Nd:YAG powder tablet, operates at quasi-continuous- wave regime pumped by a laser diode array.

Single Frequency Ytterbium Fiber Laser From Linear Cavity with Loop Mirror Filter

Single frequency ytterbium fiber laser was demonstrated by combining polariztion controller and loop mirror filter in linear laser cavity. Spatial hole burning effect was eliminated by adjusting polarization controller appropriately. The loop mirror with unpumped ytterbium fiber as a narrow bandpass filter can discriminate laser longitudinal modes efficiently. Output power up to 11.7 mW at 1064 nm were obtained for lauched pump power of 68 mW at 976 nm, the slope efficiency is about 22%.