Second-harmonic generation from thermally-poled twin-hole silica-glass optical fiber and enhancement by quasi phase matching

作者：Mizunami Toru^*; Sadakane Yasukazu; Tatsumoto Yuhei

来源：Thin Solid Films, 2008, 516(17): 5890-5893.

DOI：10.1016/j.tsf.2007.10.030

• silica glass
• optical fiber
• second-harmonic generation
• second-order nonlinearity
• poling
• space charge layer
• quasi phase matching
• germanosilicate glass

The second-harmonic generation from optical fibers was studied using a twin-hole fiber. Metal wire electrodes were inserted into the holes of 35 mu m phi, and the poling voltage was applied to a 20-mu m-thick layer including the germanosilicate core. Q-switched Nd:YAG laser pulses were coupled to the core of the fiber, and the second-harmonic wave was measured with a photomultiplier. The quasi phase matching was performed by periodic erasure of nonlinearity. The poled fiber was irradiated with a KrF excimer laser through a silica mask patterned with a 40-mu m pitch chromium stripe. By changing the angle of the fiber with respect to the mask pattern the optimum period was found to be 41.1 mu m, then the second-harmonic power increased by a factor of up to 15. Mechanisms of thermal poling and ultraviolet depoling were discussed.

• 出版日期2008-7-1