Study on highly efficiency micro optical isolators utilizing Lamipols

成功地完成了这项研究，并用GBIG制作了一个法拉第旋转器和两个薄膜片，制成了具有高隔离度的超小型光隔离器。在下文中，总结了所获得的结果。拉米波尔的光学特性主要取决于金属层的介电常数。我们用不同的沉积工艺和条件对金属薄膜进行了实验研究。我们提出用光学导纳轨迹来表示光学常数，以可视化金属中各个光学过程的相互作用。在充分减小O2影响的情况下，制备的Al膜的光学性质与块体Al几乎相同。我们利用专门设计的射频溅射系统制作了拉米波尔薄膜。获得了消光比为47d B、插入损耗为0.12d B的拉米波尔晶体。我们提出了一种利用顶部种子溶液生长法(GBIG)生长石榴石的技术。在高温溶液中生长出了尺寸较大、分布均匀、几乎没有熔剂包裹体的GBIG单晶。光隔离器我们提出并制作了光纤填充的光隔离器，通过局域热处理技术利用扩束光纤。它们有一个特殊的特点，那就是它们没有镜头系统。内嵌的隔离器为石榴石晶体(厚度=250微米)，夹在两个厚度为30微米的拉米波尔之间。在插入损耗很小的情况下，获得了超过40db的反向损耗。

The research has been completed successfully, and a very small optical isolator with high isolation has been fabricated by using two lamipols and a faraday rotator made of GBIG. In the following, results obtained are summarized.1. Lamipols Optical characteristics of Lamipols depend mainly on the dielectric constant of metal layers. We studied experimentally metal films by different deposition techniques and conditions. And we proposed the use of the optical admittance locus as the representation of the optical constants in order to visualize the interplay of each optical process in metals. The optical property of AL films is found to be almost the same as bulk AL if those are made in condition that influence of O_2 is reduced adequately. We fabricated Lamipols by specially designed rf sputtering system. We have obtained Lamipols whose extinction ratio is 47dB and whose insertion loss is 0.12dB at = 1.3mum.2. GBIG We proposed a technique while utilized top seeded soludion groth method for growth of garnets (GBIG). Relatively large and homogeneous GBIG single crystals which are nealy free from flux inclusions have been grow from a high-temperature solution.3. Optical Isolators We proposed and fabricated fiber-empedded optical isolators which utilized a beam expanding fiber by a localized heat-treatment technique. Those have a specific feature that they include no lens system. The embedded isolator is a garnet crystal (the thickness = 250mum) sandwiched between two Lamipols with the thickness of 30 mum each. We obtained a backward loss in excess of 40dB, with small insertion loss.