外国特許コード F180009427
整理番号 外0154,5712
掲載日 2018年6月28日
出願国 世界知的所有権機関(WIPO)
国際出願番号 2018JP007246
国際公開番号 WO 2018159606
国際出願日 平成30年2月27日(2018.2.27)
国際公開日 平成30年9月7日(2018.9.7)
  • 特願2017-035887 (2017.2.28) JP
発明の名称 (英語) PHOTONIC CRYSTAL LASER 新技術説明会
発明の概要(英語) A photonic crystal laser 10 is a laser having a configuration in which a light emitting layer (active layer 12) for producing light including light of a wavelength λL, and a two-dimensional photonic crystal layer 11 are laminated, the two-dimensional photonic crystal layer 11 having a refractive index distribution formed by two-dimensionally arranging, on a plate-like substrate 112, different refractive index regions (holes 111) having refractive indexes different from that of the substrate 112. In the two-dimensional photonic crystal layer 11, the different refractive index regions are arranged at positions displaced from the lattice points of a fundamental two-dimensional lattice having a periodicity which is determined such that a resonant state of the light of the wavelength λL is formed by forming a two-dimensional standing wave, and such that the light of the wavelength λL is not externally emitted. A position displacement vector Δr↑ which indicates the displacements of the positions of the different refractive index regions in the respective lattice points from the lattice points is expressed by Δr↑ = d·sin(±G'↑·r↑ + ψ0)·(cos(L(φ + φ0)) and sin(L(φ + φ0))), using: an inverse lattice vector G'↑ = ±(kx ± |k↑|(sinθcosφ)/neff, ky ± |k↑|(sinθsinφ)/neff) expressed by a wave number vector k↑ = (kx, ky) of the light of the wavelength λL in the two-dimensional photonic crystal layer 11, an effective refractive index neff of the two-dimensional photonic crystal layer, an azimuth angle φ from a predetermined reference line extending in a predetermined direction from a predetermined origin of the fundamental two-dimensional lattice, an arbitrary constant φ0, and an expanding angle θ of a laser beam; a position vector r↑ of each of the lattice points; arbitrary constants d and ψ0; and an integer L other than 0.
従来技術、競合技術の概要(英語) BACKGROUND ART
Of the sample or a small amount of fine processing is used to detect the light source, wherein the processing or to enhance the accuracy of the detection, condenses the laser beam can be as small as possible is demanded.However, simply referred to as a light condensing lens for condensing the laser beam only, the size of the spot diameter of the laser beam, the wavelength of the laser and a condensing lens of the diffraction determined by the numerical aperture cannot be below a limit value.
Patent Document 1 is, to reduce the spot diameter that is suitable as a laser generating a laser beam, a laser beam having the active layer and the photonic crystal (photonic crystal laser) is described.Photonic crystal laser, current is injected into the active layer are generated by the light, the refractive index of the photonic crystal corresponding to the period of only a specific wavelength of light selectively amplified by the interference, to cause laser oscillation.The period of the refractive index in the photonic crystal, in general, and the same order as the wavelength of light.Patent Document 1 of the photonic crystal laser, the photonic crystal is constituted, in the plate-like base material, base material is a refractive index different from refractive index region in a circular area, in circumferential direction of the ring is disposed so as to align.Each of the modified refractive index region, that passes through the center thereof extending in the radial direction of the ring has a shape asymmetrical with respect to the axis.By having such a photonic crystal, photonic crystal laser of Patent Document 1, as shown in Fig. 15 (a), the annular ring 81 is a cross-sectional view in the radial direction (direction indicated by the arrow in the figure) the laser beam having a polarization.Hereinafter, such a laser beam is' radially polarized annular laser beam ' is called.
Such a radially polarized annular laser beam by focusing, the focus in the vicinity of the electric field is generated in the optical axis direction, the diffraction limit that is less than the beam diameter of the laser beam is obtained.In the prior art, a small beam diameter to the wavelength of the optical axis direction is very narrow (short) 1 only in the region was not obtained, by using a radially polarized annular laser beam 10 in the wavelength region longer than can be obtained.
In addition, as shown in Fig. 15 (b), a radially polarized annular laser beam 83 is focused in the lens, the annular portion of the laser beam is refracted at the electric field of the radially polarized, (z direction) in a direction parallel to the laser beam of the component occurs.Polarized light having such a component is used, for example Raman scattering measurement, a laser beam in the case of using polarized light perpendicular to the scattering does not occur can be observed, an advantage (see Non-Patent Document 1).
  • 出願人(英語)
  • ※2012年7月以前掲載分については米国以外のすべての指定国
  • 発明者(英語)
  • NODA, Susumu
  • KITAMURA, Kyoko
  • YONE, Masako