飞秒激光光刻波导偏振器

飞秒激光诱导折射率变化提供了一种灵活的三维光子器件制作手段.飞秒激光光刻的II类波导具有偏振导光特性，可以作为波导偏振器，但是对于要保留的偏振分量损耗太大.本文阐述了一种利用飞秒激光在熔融石英中制作的新型低损耗波导偏振器.它由中间的一根I类波导及两侧的两根II类纳米光栅轨迹构成.基于飞秒激光诱导的纳米光栅的偏振依赖散射特性，II类纳米光栅轨迹能够对I类波导的倏逝场进行调制.偏振方向垂直于纳米光栅的模式相对于偏振方向平行于纳米光栅的模式有更大的散射损耗，因此导通的是偏振方向平行于纳米光栅的模式.研究了消光比随I类波导与II类纳米光栅轨迹之间的间距的变化关系，选择一个最佳间距来进一步研究消光比随II类纳米光栅轨迹长度的变化关系.在间距6 μm，II类纳米光栅轨迹扫描长度6 mm处实现了最大15.91 dB的消光比.通过增加II类轨迹的长度或者数量，很容易得到更高的消光比.

Abstract

Femtosecond laser inducing refractive index modification has provided a flexible avenue to three-dimensional photonic devices. Having polarization dependent guiding properties, femtosecond photowritten type II waveguide can be used as waveguide polarizer, but it experiences high loss for reserved polarization component. A new type of low loss waveguide polarizer fabricated in fused silica using femtosecond laser was reported. It consists of a type I waveguide in the middle and two type II nanograting traces on both sides. Based on the polarization dependent scattering properties of nanograting indued by femtosecond laser, the evanescent field of type I waveguide was modulated by the type II nanograting traces. Because the mode having a polarization perpendicular to the nanograting experiences a higher scattering loss compared with the mode having a polarization parellel to the nanograting, the latter was transmitted more efficiently. Firstly, polarization extinction ratio as a function of the separation between type I waveguide and type II nanograting trace was investigated. Using the best separation, polarization extinction ratio as a function of the length of type II nanograting trace was further investigated. Extinction ratio up to 15.91 dB between orthogonal polarizations have been realized with a separation of 6 μm and a type II nanograting trace length of 6 mm. Higher extinction ratio could be easily realized by increasing the length of type II nanograting traces or the amount of type II nanograting traces.

参考文献

[1] GARMIRE E M, STOLL H. Propagation losses in metal-film-substrate optical waveguide［J］. IEEE Journal of Quantum Electronics, 1972, 8(10): 763-766.

[2] THYAGARAJAN K, DIGGAVI Supriya, GHATAK A K, et al. Thin-metal-clad waveguide polarizers: analysis and comparision with experiment［J］. Optics Letters, 1990, 15(18): 1041-1043.

[3] NAKANO T, BABA K, MIYAGI M. Insertion loss and extinction ratio of a surface Plasmon-polariton polarizer: theoretical analysis［J］. JOSA B, 1994, 11(10): 2030-2035.

[4] CHEN C H, WANG L K. Design of finite-length metal-clad optical waveguide polarizer［J］. IEEE Journal of Quantum Electronics, 1998, 34(7): 1089-1097.

[5] FUJITA J, LEVY M, SCARMOZZINO R, et al. Integrated multistack waveguide polarizer［J］. IEEE Photonics Technology Letters, 1998, 10(1): 93-95.

[6] WATANABE O, TSUCHIMORI M, OKADA A, et al. Mode selective polymer channel waveguide defined by the photoinduced change in birefringence［J］. Applied Physics Letters, 1997, 71(6): 750-752.

[7] MORAND A, SANCHEZ-PEREZ C, BENECH P, et al. Integrated optical waveguide polarizer on glass with a birefringent polymer overlay［J］. IEEE Photonics Technology Letters, 1998, 10(11): 1599-1601.

[8] ICHIKAWA J, UDA S, SHIMAMURA K, et al. Ti∶LiNbO3 waveguide polarizer with a Zn-doped overlayer prepared by liquid-phase epitaxy［J］. Applied Physics Letters, 2000, 76(12): 1498-1500.

[9] ZHAO Deng-tao, SHI Bin, JIANG Zui-min, et al. Silicon-based optical waveguide polarizer using photonic band gap［J］. Applied Physics Letters, 2002, 81(3): 409-411.

[10] SINHA R K, KALRA Y. Design of optical waveguide polarizer using photonic band gap［J］. Optics Express, 2006, 14(22): 10790-10794.

[11] DAVIS K M, MIVRA K, SUGIMOTO N, et al. Writing waveguides in glass with a femtosecond laser［J］. Optics Letters, 1996, 21(21): 1729-1731.

[12] NOLTE S, WILL M, BURGHOFF J, et al. Femtosecond waveguide writing: a new avenue to three-dimensional integrated optics［J］. Applied Physics A, 2003, 77(1): 109-111.

[13] CHENG G, MISHCHIK K, MAUCLAIR C, et al. Ultrafast laser photoinscription of polarization sensitive devices in bulk silica glass［J］. Optics Express, 2009, 17(12): 9515–9525.

[14] MISHCHIK K, CHENG G, HUO G, et al. Nanosize structural modifications with polarization functions in ultrafast laser irradiated bulk fused silica［J］. Optics Express, 2010, 18(24): 24809-24824.

[15] KAZANSKY P G, SHIMOTSUMA Y. Self-assembled sub-wavelength structures and form birefrigence created by femtosecond laser writing in glass: properties and applications［J］. Journal of the Ceramic Society of Japan, 2008, 116(10): 1052-1062.

[16] TAYLOR R, HNATOVSKY C, SIMOVA E. Applications of femtosecond laser induced self-organized planar nanocracks inside fused silica glass［J］. Laser and Photonics Reviews, 2008, 2(1-2): 26-46.

林灵, 杨小君, 白晶, 龙学文, 吕百达, Razvan Stoian, 惠荣庆, 程光华. 飞秒激光光刻波导偏振器[J]. 光子学报, 2011, 40(6): 818. LIN Ling, YANG Xiao-jun, BAI Jing, LONG Xue-wen, LV Bai-da, Razvan Stoian, HUI Rong-qing, CHENG Guang-hua. Femtosecond Laser Photoinscription of Waveguide Polarizer[J]. ACTA PHOTONICA SINICA, 2011, 40(6): 818.

飞秒激光光刻波导偏振器

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