1989 Fiscal Year Final Research Report Summary
Ultra Thin Optical Fiberscope Using Phase Conjugate Wave
| Project/Area Number |
63850087
|
|---|
| Research Category |
Grant-in-Aid for Developmental Scientific Research
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
計測・制御工学
|
|---|
| Research Institution | Tokyo Institute of Technology |
|---|
Principal Investigator |
SATO Takuso Tokyo Institute of Technology, The Graduate School at Nagatsuta, Department of Precision Machinery Systems, Professor, 大学院総合理工学研究所, 教授 (20016760)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
YAMAKOSHI Yoshiki Tokyo Institute of Technology, The Graduate School at Nagatsuta, Department of P, 大学院総合理工学研究所, 助手 (10174640)
|
|---|
| Project Period (FY) |
1988 – 1989
|
| Keywords | Phase conjugated wave / Fiberscope / Nondestructive Testing / 非破壊検査 |
|---|
| Research Abstract |
Optical fiberscopes have played an important role in medical diagnosis and nondestructive measurements, and the image characteristics have recently been remarkably improved. The object is observed directly on the basis of transmission of the optical information itself, so it is essential for the observation of optical fields. But in conventional optical fiberscopest the image resolution is restricted by fiber size, because each fiber of the fiber bundle corresponds to an image Dixel in these systems. As an alternative to this fiber bundle, a method transmitting the image directly by using a fiber having a lenslike index variation has also been shown but in this case only straight and relatively short fiber can be used.
On the other hand, by using phase conjugation a possible new fiberscope that achieves the reconstruction of the object's field with only a single multimode fiber is produced and demonstrated. The required phase conjugate wave can be generated by putting the fiber's output
… More
field through a Phase conjugator; the image is retransmitted through a single fiber with the same characteristics. Hence, in this system a pair of fibers with the same characteristics must be provided. However, it is difficult to fabricate two fibers with the same characteristics, and to avoid this problem in this research time sharing between read and write processing combined into a single fiber was proposed. This procedure leads to discarding real-time processing; the requirements on the fiber are greatly reduced and noise caused by extraneous light is eliminated completely.
Demonstrations are shown of the actual observation of small objects using this scheme. For this purpose, the required source of illumination is made by assembling a microlens with a second fiber, thus a compact and very thin fiberscope having a size of about twice the diameter of a single multimode fiber is achieved. The results of observing a 3-D field of small objects yield the 3-D resolution of the system. In addition, the effects of fiber bending are also discussed. Results of observation of IC chips were shown. Less
|
Research Products
(6 results)
