Laser element and laser device

Patent metadata

Field	Value
Publication number	US-9614352-B2
Application number	US-201414772532-A
Country	US
Kind code	B2
Filing date	Mar 7, 2014
Priority date	Mar 7, 2013
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

The coordinates of an unit configuration region R 11 is (X1, Y1), and the coordinates of an unit configuration region Rmn is (Xm, Yn) (m and n are natural numbers). Rotation angles φ with respect to a center of apexes of an isosceles triangle are different according to coordinates, and at least three different rotation angles φ are contained in all of the photonic crystal layer.

First claim

The invention claimed is:

1. A laser element including a photonic crystal layer on which laser light is incident, wherein
the photonic crystal layer comprises:
a base layer formed of a first refractive index medium; and
a plurality of different refractive index regions formed of a second refractive index medium having a refractive index different from that of the first refractive index medium and disposed in the base layer,
the plurality of different refractive index regions has a plane shape that is an approximate triangle, an approximate ellipse in which a flatness ratio is not zero, or a non-rotational symmetric shape,
a unit configuration region is formed of one different refractive index region,
in the unit configuration region, a rotation angle of one point on a contour of the plane shape with respect to a central position of the different refractive index region is denoted by φ,
in an XY plane including an X axis and an Y axis, a plurality of the unit configuration regions is two-dimensionally arranged,
XY coordinates of each of the unit configuration regions is given to a central position of the different refractive index region,
when the XY coordinates of the unit configuration region are (X, Y),
the rotation angles φ are different depending on respective positions, and
the respective rotation angles φ are set so as to satisfy a two-dimensional phase distribution of an image obtained by performing inverse-Fourier transformation on a far-field pattern image of a laser beam emitted from the laser element corresponding to a distribution of the rotation angles φ in the respective unit configuration regions.

2. The laser element according to claim 1 , further comprising:
an active layer configured to emit the laser light;
upper and lower cladding layers between which the active layer is interposed; and
the photonic crystal layer disposed between the upper or lower cladding layer and the active layer.

3. A laser device, comprising:
the laser element according to claim 1 ; and
a polarizing plate disposed to face a light emitting surface of the laser element.

4. A laser device, comprising:
the laser element according to claim 2 ; and
a polarizing plate disposed to face a light emitting surface of the laser element.

5. The laser element according to claim 1 , wherein at least three different rotation angles φ are contained in all of the photonic crystal layer.

6. The laser element according to claim 1 , wherein a laser beam is inclined from a direction perpendicular to a light emitting surface of the laser element.

7. The laser element according to claim 5 , wherein a laser beam is inclined from a direction perpendicular to a light emitting surface of the laser element.

Assignees

• Hamamatsu Photonics Kk

Inventors

• Takiguchi Yuu
• Nomoto Yoshiro

Classifications

• H01S5/12

  the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers (comprising a photonic bandgap structure H01S5/11; surface-emitting lasers H01S5/18) · CPC title

• H01S5/34313

  with a well layer having only As as V-compound, e.g. AlGaAs, InGaAs · CPC title

• G02B27/286

  for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another (G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34) · CPC title

• H01S2301/14

  Semiconductor lasers with special structural design for lasing in a specific polarisation mode · CPC title

• H01S5/005

  Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping (H01S5/026, H01S5/18388 take precedence) · CPC title