Abstract: The present invention provides an apparatus for measuring the thickness of a material using the focal length of a lensed fiber and an associated method. The lensed fiber generates a Gaussian Beam and moves vertically with respect to the material. The strength of the beam reflected from the material is detected when the beam emitted from the lensed fiber is focused on the material. The thickness of the material is calculated based upon the detected strength of the reflected beam.

Abstract: The figure-8 optical fiber pulse laser according to the present invention produces stable femto-second optical pulses using DI-NOLM. The optical amplifier is not included in DI-NOLM, instead, it is located at the unidirectional linear loop part. And the noise due to the bidirectional gain difference of the optical amplifier is reduced. Two optical fibers of different dispersion values are used at DI-NOLM. Therefore, the present invention provides a figure-8 optical fiber pulse laser using DI-NOLM improving the switching characteristic. Especially, the stable femto-second laser according to the present invention is applicable for the many applications such as high-speed reaction measurements, laser treatments, and medical lasers.

Abstract: The present invention relates to an apparatus for measuring the thickness of materials using the focal length of a lensed fiber and a method thereof. More particularly, the invention relates to a method of measuring the thickness of materials using the strength of the beam reflected from the focal length when the beam emitted from a lensed fiber is focused on a material.

Abstract: The present invention relates to a figure-8 optical fiber pulse laser using a dispersion imbalanced nonlinear optical loop mirror (DI-NOLM). The conventional figure-8 optical fiber pulse laser uses a nonlinear optical fiber mirror having an EDF as a gain material. The conventional laser has an advantage for the simple structure, and it can be easily constructed. However, it can not produce the stable optical pulse trains.

Abstract: Disclosed are an apparatus and method for measuring the refractive index distribution of an optical fiber or waveguide by measuring a variation in reflectivity on the surface of the optical fiber or waveguide depending upon the position on the surface of the optical fiber or waveguide while scanning the optical fiber or waveguide surface at a fixed scanning height using three laser beams of different wavelengths projected onto the optical fiber or waveguide surface. In accordance with the present invention, a high spatial resolution is obtained, as compared to conventional measuring devices using a refraction phenomenon. It is also possible to remarkably reduce measuring errors because a high signal-to-noise ratio is provided, as compared to conventional measuring devices using a scanning near field optical microscope.