[en] We demonstrate visible-light all-fiber vortex lasers by incorporating the home-made mode selective couplers (MSCs). The MSC at green or red wavebands is fabricated by specially designing and fusing a single-mode fiber (SMF) and a few-mode fiber (FMF). The MSCs inserted into visible fiber cavities act as power splitters and mode converters from the LP₀₁ to LP₁₁ mode at green and red wavelengths, respectively. The red-light all-fiber vortex laser is formed by a 10-cm Pr³⁺/Yb³⁺:ZBLAN fiber, a fiber Bragg grating, a fiber end-facet mirror and the MSC at 635 nm, which generates vortex beams with OAM_±1 at 634.4 nm and an output power of 13 mW. The green-light all-fiber vortex laser consists of a 12-cm Ho³⁺:ZBLAN fiber, two fiber pigtail mirrors, and the MSC at 550 nm, which generates vortex beams with OAM_±1 at 548.9 nm and an output power of 3 mW. (special topic)

[en] A sandwich-type laser device with a surface-relief grating inside was infiltrated with dye-doped nematic liquid-crystals which functioned as gain media. The surface-relief grating was fabricated by soft lithographic technique on a sol–gel derived zirconium-doped hybrid film using a polydimethyl–siloxane replica. The optical properties of the distributed feedback (DFB) resonator were modified by introducing a high refractive index layer consisting of niobium pentoxide subsequently. Thermal induced shift of amplified spontaneous emission spectrum, switching of multi-wavelength DFB laser emission and occurrence of random lasing were demonstrated.