Abstract: A method of fabricating an axially symmetric liquid crystal lens is disclosed, which comprises steps: (A) providing a first substrate; (B) forming a first conductive layer on the first substrate; (C) forming a first resist layer on the first conductive layer; (D) forming a first pattern with sub-micrometer period in the first resist layer by laser scanning; (E) developing the first resist layer to obtain a first patterned layer with sub-micrometer period; (F) providing a second substrate; and (G) forming a liquid crystal layer between the first patterned layer and the second substrate, wherein the first substrate, the first conductive layer, the first patterned layer, the liquid crystal layer, and the second substrate are sequentially arranged to form a layered structure. Also, an axially symmetric liquid crystal lens and liquid crystal alignment substrate for liquid crystal lens provided by the same are disclosed.

Abstract: 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.

Abstract: A method of fabricating an axially symmetric liquid crystal lens is disclosed, which comprises steps: (A) providing a first substrate; (B) forming a first conductive layer on the first substrate; (C) forming a first resist layer on the first conductive layer; (D) forming a first pattern with sub-micrometer period in the first resist layer by laser scanning; (E) developing the first resist layer to obtain a first patterned layer with sub-micrometer period; (F) providing a second substrate; and (G) forming a liquid crystal layer between the first patterned layer and the second substrate, wherein the first substrate, the first conductive layer, the first patterned layer, the liquid crystal layer, and the second substrate are sequentially arranged to form a layered structure. Also, an axially symmetric liquid crystal lens and liquid crystal alignment substrate for liquid crystal lens provided by the same are disclosed.

Abstract: 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.

Abstract: 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.

Abstract: The present invention proposes a method for modulating refractive indices of optical fiber gratings, wherein the UV exposure on a least one assigned location of an optical fiber grating is divided into to two UV shots, and the intensities or phases of the two UV shots, which expose the location sequentially, are controlled to make the total exposure intensity of one assigned location maintained at a fixed value, whereby the interference fringes, which are created by a superposition of the two UV shots, have fixed phases and adjustable intensities, and whereby the dc index of the optical fiber grating maintains fixed and the ac index independently adjustable.

Abstract: 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.

Abstract: The present invention proposes a method for modulating refractive indices of optical fiber gratings, wherein the UV exposure on a least one assigned location of an optical fiber grating is divided into to two UV shots, and the intensities or phases of the two UV shots, which expose the location sequentially, are controlled to make the total exposure intensity of one assigned location maintained at a fixed value, whereby the interference fringes, which are created by a superposition of the two UV shots, have fixed phases and adjustable intensities, and whereby the dc index of the optical fiber grating maintains fixed and the ac index independently adjustable.

Abstract: The present invention provides a fiber Bragg Grating sequential writing method with real-time optical fiber position monitoring, characterized in that the relative phase between a fiber grating and a writing interference beam at each positioning point is determined by an interferometric side-diffraction method, and writing is sequentially performed. Accuracy in fabricating a long and complex fiber grating structure can be increased by decreasing or avoiding accumulative errors caused by long-term scan of monitoring optical fiber position, or by a means for fabricating a wanted reference fiber Bragg grating with similar settings.

Abstract: The present invention provides a fiber Bragg Grating sequential writing method with real-time optical fiber position monitoring, characterized in that the relative phase between a fiber grating and a writing interference beam at each positioning point is determined by an interferometric side-diffraction method, and writing is sequentially performed. Accuracy in fabricating a long and complex fiber grating structure can be increased by decreasing or avoiding accumulative errors caused by long-term scan of monitoring optical fiber position, or by a means for fabricating a wanted reference fiber Bragg grating with similar settings.