- Namiki 1-1, Tsukuba, Ibaraki, JAPAN
- Working on optical fibers exposed with high power laser beam. Interested in digital publishing using free software,... moreWorking on optical fibers exposed with high power laser beam.
Interested in digital publishing using free software, including writing light essays (see Papers on the left).
Completed my PhD in engineering at Kyoto University in 1993.edit
An actual example is demonstrated for the case of one-dimensional combinatorial glass sample library. Some tellurite glass libraries containing Er and F are annealed in a temperature-gradient furnace and the decay curves of... more
An actual example is demonstrated for the case of one-dimensional combinatorial glass sample library. Some tellurite glass libraries containing Er and F are annealed in a temperature-gradient furnace and the decay curves of 1.5µm-fluorescence of Er3+ are recorded along the libraries in order to find annealing conditions for precipitation of Er-containing fluoride crystals.
Excessive-light-induced melt down was observed in a carbon-coated TeO2 glass segment formed between a pair of optical fiber end-faces. This structure was made by splicing single-mode silica fibers through TeO2 glass melt to form a necked... more
Excessive-light-induced melt down was observed in a carbon-coated TeO2 glass segment formed between a pair of optical fiber end-faces. This structure was made by splicing single-mode silica fibers through TeO2 glass melt to form a necked bridge, which was coated with carbon-containing paint after quenching it. Optical fusing action was induced by 0.3–1.5 W of CW light (1.54µm) and its output power dropped by 12 dB on average. Optical decoupling seems to be induced by not only deformation but also crystallization of the glass bridge.
Background Fiber fuse is a process of optical fiber destruction under the action of laser radiation, found 20 years ago. Once initiated, opical discharge runs along the fiber core region to the light source and leaves periodic voids whose... more
Background Fiber fuse is a process of optical fiber destruction under the action of laser radiation, found 20 years ago. Once initiated, opical discharge runs along the fiber core region to the light source and leaves periodic voids whose shape looks like a bullet pointing the direction of laser beam. The relation between damage pattern and propagation mode of optical discharge is still unclear even after the first in situ observation three years ago.
Abstract Since I have been publishing my research papers mainly in open access journals, most of my self-archived articles, including English translations, are originally published in domestic journals. Although such publications are not... more
Abstract Since I have been publishing my research papers mainly in open access journals, most of my self-archived articles, including English translations, are originally published in domestic journals. Although such publications are not evaluated for my academic accomplishments, I continue this activity because I want to share the following two things beyond my own special field.(1) Serendipitous episodes that are not allowed to publish in academic journals and (2) knowhow that is useful for research activities.
The combinatorial methodologies have been studied to automate the process for the determination of glass-forming region. The glass batches were prepared automatically and were melted simultaneously by applying various heating techniques,... more
The combinatorial methodologies have been studied to automate the process for the determination of glass-forming region. The glass batches were prepared automatically and were melted simultaneously by applying various heating techniques, followed by cooling to room temperature to get the melt-quench samples. In this study, the combinatorial methods for the preparation of batches and the melting in the crucibles have been developed.
光ファイバが長距離に渡って破壊される現象であるファイバヒューズに関して, 現在までに分っていることをまとめたのち, 筆者の研究を紹介する. 毎秒約 1m で動くファイバヒューズを超高速カメラで撮影し, また残された損傷の光学顕微鏡映像を統計処理することで, 損傷発生のメカニズムについて推理する.
概要 通信用光ファイバに関する話題として, 孔を空けて特異な物性を引き出すホーリーファイバと, 光による破壊の連鎖で孔が空いていくファイバフューズを紹介する. 波長変換素子や超広帯域光源への応用を目指した, 非線型光学係数の大きい材料を使ったフォトニック結晶光ファイバの最近の動向を概観する. また, 20 年前に発見されたファイバフューズ現象を最新の超高速カメラで撮影し, 併せて空孔生成メカニズムを提案した筆者の仕事を紹介する.
Low loss (less than 1dB) passive optical fuses were realized by inserting 50-µm-thick TeO2 glass layer into a single-mode silica glass fiber circuit with carbon coating. On the basis of real-time observation of their fusing action, the... more
Low loss (less than 1dB) passive optical fuses were realized by inserting 50-µm-thick TeO2 glass layer into a single-mode silica glass fiber circuit with carbon coating. On the basis of real-time observation of their fusing action, the mechanism of losing its transparency is discussed. The observed loss drop is found to be an overlap of decoupling of the circuit and transient light flux from the burned coating. The critical input power to blow out is expected to be raised by eliminating its insertion loss.
A series of optical micrographs showing the front region of fiber fuse damage were obtained to reveal the periodic void formation process. They were collected from a number of samples and were sorted in order of increasing distance... more
A series of optical micrographs showing the front region of fiber fuse damage were obtained to reveal the periodic void formation process. They were collected from a number of samples and were sorted in order of increasing distance between the top of the first large void and the top of the first regular void. The micrographs clearly show that the first large void sheds its tail, which shrinks to form a regular void.
Several nano liters of tellurite glass melt was inserted and quenched between two ends of silica glass optical fibers to form a optical coupling structure, whose length was several hundred µm. Dispite the large gap of thermal expansion... more
Several nano liters of tellurite glass melt was inserted and quenched between two ends of silica glass optical fibers to form a optical coupling structure, whose length was several hundred µm. Dispite the large gap of thermal expansion coefficient between these glass materials, neither fracture nor bubbles were observed, which usually lead to a large optical propagation loss. The insertion loss was less than 10 dB, which was mainly due to the lack of an optical waveguide structure in the tellurite glass segment.
Brief review of fiber fuse that is seen in my portrait.