電光與熱光可調式環形濾波器之研究

Study of Electro-optically and Thermo-optically Tunable Microring Filters

朱家鴻(Chia-Hung Chu)

指導教授 ： 王子建

國立臺北科技大學/機電學院/光電工程系所/碩士(2006年)

摘要

本研究在鈮酸鋰上設計製作低損耗之S形彎曲波導，並利用所設計之脊形波導結構，研製波長可調式環形濾波器。論文中設計與製作脊形鈦擴散光波導，利用脊形結構所造成之橫向高折射率對比以及加大鈦膜寬度，使鈦膜可由脊形兩側擴散進去，增加其波導折射率值，進而降低其彎曲波導之損耗。當彎曲半徑為100μm時，傳輸光波長1550nm之TM與TE極化光，高度為5μm之脊形彎曲波導較平面彎曲波導之傳播損失可分別降低4.2dB與4.18dB。另外，當彎曲波導的脊形高度為5μm時，鈦膜寬度為12μm較鈦膜寬度6μm之傳播損失也減少0.938dB與1.002dB。
在積體光學環形濾波器的研究上，設計間距為3μm之方向耦合器應用至環形濾波器結構上，並以鈮酸鋰之電光與熱光效應來調整環形濾波器之濾波波長。當耦合長度為80μm，環形半徑為100μm時，應用電光調制方式改變環形濾波器的濾波波長，TM與TE極化光的波長調變率分別為1.61×10-3nm/V與6.07×10-4nm/V。應用熱光調制方式調整共振波長，TM與TE極化光的波長調變率分別為2.54×10-2nm/mA與3.40×10-3nm/mA。

關鍵字

環形濾波器 ； 鈮酸鋰 ； 電光效應 ； 熱光效應

並列摘要

In this study, low-loss S-bends and wavelength-tunable microring filters with a ridge waveguide structure on lithium niobate are successfully presented. A single-mode Ti-diffused ridge waveguide is fabricated and its characteristics, including optical field profile and propagation loss, are measured. Lateral high-index contrast due to the ridge structure and widened Ti strip is utilized to reduce the propagation loss of the waveguide bend. As the bend radius is 100μm, the S-bend loss of the waveguide bend with the ridge height of 5μm is smaller than that of the embedded waveguide bend by 4.2dB and 4.18dB for the TM- and TE- polarizations, respectively; as the ridge height is 5μm, the S-bend loss of the waveguide bend with the width of 12μm is smaller than that of the 6μm waveguide bend by 0.938dB and 1.002dB for the TM- and TE- polarizations, respectively.
The microring filter consists of a microring waveguide and a 3μm-gap directional coupler. The resonant wavelength of microring filters is successfully tuned by using electro-optic and thermal-optic effects. For the electro-optically tunable microring filters with coupler length of 80μm and ring radius of 100μm, the tuning rates of resonant wavelength are 1.61×10-3nm/V and 6.07×10-4nm/V for TM- and TE- polarizations, respectively； The tuning rates of resonant wavelength by thermal- optic effect for the TM- and TE- polarizations are 2.54×10-2nm/mA and 3.40×10-3nm/mA, respectively.

並列關鍵字

microring filter ； lithium niobate ； electro-optic effect ； thermal-optic effect

參考文獻

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