808-nm fiber coupled module with a CW output power up to 130 W

A fiber coupled module is fabricated with integrating the emitting light from four laser diode bars into multimode fiber bundle.The continuous wave(CW)output power of the module is about 130 W with a coupling efficiency of around 80%.The output power is very stable after the temperature cycling and vibration test.No apparent power decrease has been observed as the device working continuously for 500 h.     

4-W single transverse mode Yb~(3+)-doped fiber laser pumped by 915-nm laser diode array

A cladding-pumped ytterbium-doped fiber laser is described in this letter. Using unusual pumping source with 915-nm wavelength, slope efficiency up to 75% with respect to absorbed input power and output power is obtained, a maximum output power of 4.006 W with fundamental mode is measured.     

Optimal distance from high power laser diode to cylindrical microlens in a coupling system

In a practical coupling system, a cylindrical microlens is used to collimate the emission of a high power laser diode (LD) in the dimension perpendicular to the junction plane. Using passive alignment, the LD is placed in the focus of the cylindrical microlens generally, regardless of the performance of the multimode optical fiber and the LD. In this paper, a more complete analysis is arrived at by ray-tracing technique, by which the angle 9 of the ray after refraction is computed as a function of the angle θo of the ray before refraction. The focus of the cylindrical microlens is not always the optimal position of the LD. In fact, in order to achieve a higher coupling efficiency, the optimal distance from the LD to the cylindrical microlens is dependent on not only the radius R and the index of refraction n of the cylindrical microlens, but also the divergence angle of the LD in the dimension perpendicular to the junction plane and the numerical aperture (NA) of the multimode optical fiber. The result     

Passive Q-Switching Modelocked Yb^3＋ -Doped Fibre Laser with GaAs Absorber Grown at Low Temperature

GaAs absorber was grown at low temperature (550℃) by metal organic chemical vapour deposition (MOCVD)and was used as an output coupler with which we realized Q-switching modelocked yb^3 -doped fibre laser. The shortest period of the envelope of the Q-switched modelocking is about 31μs. The modelocking threshold is 4.27 W and the highest average output pulse power is 290mW. The modelocking frequency is 12 MHz.