National Yang Ming Chiao Tung University

Industrial Technology Research Institute

Yin-Chieh Lai

Kuei-Chu Hsu

Ding-Wei Huang

Tsung-Hsuan Chiu

Chen-Wei Hsin

Chia-Hua Chan

Wei-Wei Hsiang

Siao-Shan Jyu

Hon-Chieh Chang

Shiou-Fong Liu

Chii-Chang Chen

A method for measuring dispersion in an optical fiber is provided and includes the following steps. A periodic wavelength variation pulse light signal is generated by a periodic frequency-swept pulse light source, in which the periodic wavelength variation pulse light signal has periodic wavelength variations. The periodic wavelength variation pulse light signal is transmitted into a test optical fiber. The periodic wavelength variation pulse light signal propagating through the test optical fiber is detected to generate a sensing signal. The sensing signal is transformed into an RF spectrum to obtain a slow periodic pulse timing variation of the periodic wavelength variation pulse light signal in accordance with the RF spectrum. A dispersion value of the test optical fiber is obtained in accordance with the slow periodic pulse timing variation. A system for measuring dispersion in a fiber is also disclosed herein.

System and method for measuring dispersion

A displacement measurement system including a coherent light source, a two-dimensional grating, a photo sensor, and a signal processing apparatus is provided. After the coherent light beam enters the two-dimensional grating, a zero-order light beam and a plurality of first-order diffraction beams are generated. The zero-order light beam interferes with two of the first-order beams in different directions, so that corresponding interference fringes are formed on the photo sensor. Accordingly, when the two-dimensional grating moves, displacements of the two-dimensional grating in the different directions are obtained by calculating phase differences of the interference fringes in the corresponding directions. Besides, when the two-dimensional grating rotates, the rotational angle of the two-dimensional grating is obtained from the corresponding rotational angle of a diffraction pattern of the first-order diffraction beams.

Displacement measurement system and method thereof

A new fiber position monitoring method for sequential FBG UV-writing processes with a reference phase mask as the phase reference is proposed. Also, the new method by probing a reference phase mask can overcome the optical alignment difficulties in using reference fiber as well as provide more signal power for achieving better monitoring accuracy. Moreover, the present invention provides a method for sequentially joining a plurality of grating sections into a fiber grating longer than a phase mask.

Long-length fiber Bragg creating sequential UV writing by probing phase mask

Along with several few-channel and low-density wavelength division multiplexer/de-multiplexer, a novel planar lightwave circuit (PLC) interleaver is invented to achieve high-density wavelength division multiplexing and de-multiplexing in a wavelength division multiplexing fiber communication system. The invention uses a PLC as its basic structure and applies the principle that the product of the number of output optical waveguides and the channel spacing is equal to the free spectral range of the spectrum of any output optical waveguide to make a compact PLC interleaver.

Planar lightwave circuit interleaver

Growing community of inventors

Taichung, Taiwan

Yin-Chieh Lai