Abstract: A producing method of an optical element such as quarter-wave plate wherein preparing a first member which has a coefficient of elasticity of 1-4 (GPa) at normal temperature, setting the temperature of a die having microscopic shape with high aspect ratio to be higher than the glass transition temperature of the first member and pressing the die against the first member to transfer a microscopic shape on the first member, a microstructure is formed on the first member. In the same manner, a second microstructure is formed on a second member. Afterwards, by connecting the first member and the second member, an optical element in which the first member and the second member are connected having microstructures with high aspect ratio face each other, is obtained.

Abstract: There is described a molding method for molding a product, having a microscopic structure of high aspect ratio. The molding method includes the steps of: setting a temperature of a mold, having a microscopic shape, at a value higher than a glass transition temperature of a material being deformable with heat; pushing the mold against the material at a first velocity, after the material is positioned opposite to the mold so that the microscopic shape contacts the material; pushing the mold against the material at a second velocity being faster than the first velocity; and releasing the mold from the material. The pushing pressure for pushing the mold against the material at the first velocity is equal to or smaller than a half of that for pushing the mold against the material at the second velocity.

Abstract: A wide-band wave plate having at least two wave plates, each of which has a microstructure to generate a phase difference, the microstructure having a cycle not shorter than 1/nmin of a shortest wavelength of light in use, wherein the two wave plates are arranged to face opposite with their main axes in non-parallel with each other, wherein nmin is a refractive index of a wave plate material with respect to the shortest wavelength.

Abstract: An echelon type diffraction structure 5a is formed on the flat optical surface of a lens 5, thereby ensuring easy designing and easy production of a diffraction structure as a microstructure. Further, the light of wavelength ?1 is applied to the diffraction structure 5a in a tilted position with respect to the optical axis of the lens 5 so that the first order diffracted light produced by the diffraction structure 5a travels along or parallel to the optical axis of the lens 5, with the result that improved light transmittance can be maintained. Further, a lens 7b is arranged between a light emitting device 7a and lens 5. Thus, the flat optical surface of the lens 5 is arranged on the side of the end face 1a of an optical fiber 1, thereby reducing the deterioration in aberration more effectively.

Abstract: A wide-band wave plate having at least two wave plates, each of which has a microstructure to generate a phase difference, the microstructure having a cycle not shorter than 1/nmin of a shortest wavelength of light in use, wherein the two wave plates are arranged to face opposite with their main axes in non-parallel with each other, wherein nmin is a refractive index of a wave plate material with respect to the shortest wavelength.

Abstract: An echelon type diffraction structure 5a is formed on the flat optical surface of a lens 5, thereby ensuring easy designing and easy production of a diffraction structure as a microstructure. Further, the light of wavelength ?1 is applied to the diffraction structure 5a in a tilted position with respect to the optical axis of the lens 5 so that the first order diffracted light produced by the diffraction structure 5a travels along or parallel to the optical axis of the lens 5, with the result that improved light transmittance can be maintained. Further, a lens 7b is arranged between a light emitting device 7a and lens 5. Thus, the flat optical surface of the lens 5 is arranged on the side of the end face 1a of an optical fiber 1, thereby reducing the deterioration in aberration more effectively.

Abstract: A producing method of an optical element such as quarter-wave plate wherein preparing a first member which has a coefficient of elasticity of 1-4 (GPa) at normal temperature, setting the temperature of a die having microscopic shape with high aspect ratio to be higher than the glass transition temperature of the first member and pressing the die against the first member to transfer a microscopic shape on the first member, a microstructure is formed on the first member. In the same manner, a second microstructure is formed on a second member. Afterwards, by connecting the first member and the second member, an optical element in which the first member and the second member are connected having microstructures with high aspect ratio face each other, is obtained.

Abstract: There is described a molding method for molding a product, having a microscopic structure of high aspect ratio. The molding method includes the steps of: setting a temperature of a mold, having a microscopic shape, at a value higher than a glass transition temperature of a material being deformable with heat; pushing the mold against the material at a first velocity, after the material is positioned opposite to the mold so that the microscopic shape contacts the material; pushing the mold against the material at a second velocity being faster than the first velocity; and releasing the mold from the material. The pushing pressure for pushing the mold against the material at the first velocity is equal to or smaller than a half of that for pushing the mold against the material at the second velocity.