All-fiber acousto-optic modulator based on a cladding-etched optical fiber for active mode-locking

作者：Kim Jihwan; Koo Joonhoi; Lee Ju Han^*

来源：Photonics Research, 2017, 5(5): 391-395.

DOI：10.1364/PRJ.5.000391

An all-fiber acousto-optic modulator (AOM), which features a compact structure and a low-driving voltage, is experimentally demonstrated for the active mode-locking of a fiber laser. The proposed AOM is based on the short length of the cladding-etched fiber, the ends of which are fixed on a slide glass. On top of the cladding-etched fiber, a piezoelectric transducer was overlaid. A chemical wet-etching technique, which is based on a mixed solution of NH4F and (NH4)(2)SO4, is used to reduce the fiber diameter down to similar to 25 mu m, and the length of the etched section is only 0.5 cm. The fabricated device exhibited a modulation depth of 73.10% at an acoustic frequency of 918.9 kHz and a peak-to-peak electrical voltage of 10 V, while a laser beam was coupled at 1560 nm. By using the prepared AOM within an erbium-doped-fiber ring cavity, the mode-locked pulses with a temporal width of 2.66 ps were readily obtained at a repetition rate of 1.838 MHz.

• 出版日期2017-10-1