局域铒、铥共掺钛扩散铌酸锂光波导及相关器件实验研究

Based upon a large number of already accomplished own preparatory works, the principal investigator and his co-workers propose firstly the peculiar and novel research idea of developing locally Er3+/Tm3+-codoped titanium-diffused LiNbO3 strip optical waveguide to solve the crucial scientific problem of photorefractive damage from which a LiNbO3-based active optical waveguide device currently suffers. Codoped with Tm3+ ion not only can suppress the photorefractive effect, but also allows to utilize its luminescence properties. Moreover, it is possible to simultaneously realize the broadband amplification covering the S+C+L wavelength range. The succeeding in developing such waveguide enables to establish an important support platform for the development of many novel photorefractive-damage-resistant active devices and the storage of quantum information. The major research contents include: 1) Setup a combined method of Li-poor vapor transport equilibration (VTE) technology and metal-indiffusion used for fabrication of low-loss, locally heavily Er3+/Tm3+-codoped, photorefractive-damage-resistant Ti:Er:Tm:LiNbO3 strip waveguides. 2) To examine the applicability of the waveguides fabricated, we will exemplify to develop some devices including 1.47 and 1.55 μm waveguide amplifiers, 550 nm frequency upconversion and 1.8 μm infrared waveguide lasers. Commercial low-priced 980 nm or 800 nm high-power laser diode (LD) will be used as the pumping source. These devices not only are no longer restricted by the pumping and/or operating wavelengths, but also are photorefractive-damage-resistant. The outputs of the project are of the crucial significance to promote and accelerate the step of LiNbO3-based devices to the utilization stage. The proposed project possesses solid ground and good continuity of research work, as well as necessary facilities.

在已完成大量相关工作基础上提出研制局域Er、Tm共掺钛扩散铌酸锂(LN)光波导来解决铌酸锂基有源光波导器件所面临的关键科学问题-光损伤问题的新颖独特研究思想。共掺Tm不仅可抑制光折变效应而且还可利用其自身发光特性同时实现S+C+L波段宽带放大。成功研制该类型光波导可为多种新型抗光折变器件研发和量子信息存储构建重要支撑平台。主要研究内容：1)建立一套缺锂气相输运平衡和金属内扩散相结合方法用于制备低损耗、局域高掺Er和Tm、抗光折变Ti:Er:Tm:LN光波导；2)为考察所制备光波导的可应用性,举例研制一些不在受限于泵浦和/或工作波长的、抗光折变的有源器件包括以廉价980 或800nm LD作为泵浦源的1.47和1.55μm放大器，550nm频率上转换和1.8μm激光器。所取得的研究成果对促进LN基有源器件向实用化阶段迈进具有重要意义。本项目具有良好研究工作基础和连续性,具备必要的实验条件。

本项目提出研制局域Er、Tm共掺钛扩散铌酸锂(LN)光波导来解决相关有源器件所面临的光损伤关键科学问题。此外，共掺Tm不仅可抗光损伤而且还可利用其自身发光特性实现S+C+L波段宽带放大。. 主要研究内容：1)建立VTE和金属内扩散相结合方法用于制备高质量Ti:Er:Tm:LN光波导；2)为考察其可应用性,举例研制出了一些抗光折变有源器件包括以廉价980 或795纳米 LD作为泵浦源的1.45和1.55 μm放大器，550nm绿色频率上转换和1.8 μm激光器。. 主要研究结果：.(1)采用VTE和铒、铥共扩散相结合方法制备了局域铒、铥共掺LN基片。实验结果表明：Er3+和Tm3+共扩不会影响其各自的扩散系数，晶体中稀土离子的溶解度由Er3+和Tm3+浓度分量组成。两分量只随初始金属膜厚度相对比值的变化而变化。二者之和在一定温度下保持为常数。该常数等于各自单独扩散时的溶解度值。此外，Er3+和Tm3+共掺结合了二者在1.5微米波段发射特征（发射带宽达150纳米）。.(2)采用钛扩散技术制作出了Ti:Er:Tm:LN条形光波导。结果表明：波导表面平坦、光滑，能很好传输1.5微米TE和TM单模光波, 损耗小于0.5dB/cm。在波导宽度方向Ti浓度遵从和误差函数分布，在深度方向Ti 、Er和Tm浓度均遵从高斯分布。建立了二维折射率分布。.(3)研究了Ti:Er:Tm:LN光波导的ASE谱、抗光折变及放大性能。结果表明：1.5微米波段Er3+、Tm3+ASE特征与其各自单掺时相同，表明二者以LN晶相形式存在。共掺并不影响各自光谱性质。Tm共掺有效地提高了波导抗光折变能力。在980(795)纳米波长泵浦下，可获得的1.547(1.45)微米小信号的净增益为0.8(1.0)dB/cm。近一步证明了采用980和795纳米LD同时泵浦同一Ti:Er:Tm:LN波导实现S+C+L宽带放大的可能性。.(4)完成了Ti:Er:Tm:LN绿色上转换和1.8微米波段激光器的设计、制作和运行。在可获得980/795纳米泵浦功率430/400毫瓦下，获得了1.3/2.3毫瓦绿色/红外稳定激光输出，进一步验证了波导的抗光折变能力。经优化更高效激光性能可期。. 本项目为各种新型抗光折变有源器件研发构建重要支撑平台。所取得的研究成果对促进LN基有源器件向实用化阶段迈进具有重要意