TAKAHASHI N. Kyoto Univ., Electronics, Assistant, 工学部, 助手 (70206829)
KITANO M. Kyoto Univ., Electronics, Assoc.Professor, 工学部, 助教授 (70115830)
NAKAJIMA M. Kyoto Univ., Electronics, Assoc.Professor, 工学部, 助教授 (60025939)
|Budget Amount *help
¥6,800,000 (Direct Cost : ¥6,800,000)
Fiscal Year 1993 : ¥1,500,000 (Direct Cost : ¥1,500,000)
Fiscal Year 1992 : ¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1991 : ¥3,500,000 (Direct Cost : ¥3,500,000)
The present project is aimed to develop a new type optical STM as an optical waveguide diagnosing system, which can pick up the evanescent waves leaking from the surface of an optical waveguide or optical IC by means of a nano-probe made of a sharpened optical fiber. The optical STM syetem, which makes use of the optical tunneling effect, is supposed to be able detect very minute surface inhomogeneities on an optical waveguide. The tip of a nano-probe is assumed to be cylindrical or pencil shaped, and is immersed in the evanescent optical field.
Various characteristics of such an optical nano-probe, e.g., its sentitivity or antenna gain, directivity, dependence on the probe shape, have been studied by means of the electromagnetic field analysis and numerical calculations.
On the other hand, we have designed and constructed the optical diagnosing system, which is composed of an optical fiber nano-probe, probe-positiong and driving system, scanning component, laster driving circuit, optical detector, control circuit, etc. With this probing system, we made several experiments of measuring the thickness of SiO_2 thin films of about 150nm thick, and evaluated its performance. We find that the system is able to detect evanescent waves with sufficient accuracy and can scan a two-dimensional surface with desired stability, and that the system is able to measure thinner thickness than the laser wavelength (670nm). By measurement of evanescent waves created on a compact disk (CD) surface, we have shown the present system can observe nano-structures, such as CD pits.