摘要:
A two-dimensional photonic crystal laser according to the present invention includes a two-dimensional photonic crystal layer 15 having a base body made of AlαGa1-αAs (0
摘要:
An objective of the present invention is to provide a surface emitting laser capable of selectively generating a laser oscillation in the fundamental mode and thereby emitting a single-wavelength laser light. In a surface emitting laser including an active layer and a two-dimensional photonic crystal provided on one side of the active layer, a reflector 45 or 46 is provided at least at a portion of the circumference of the two-dimensional photonic crystal. The reflector has a reflectance distribution in which the reflectance has a maximum value at a position where the amplitude envelope of the fundamental mode of an internal resonance light created within the two-dimensional photonic crystal. This design strengthens the fundamental mode while suppressing the second mode, thus enabling the laser oscillation in the fundamental mode to be selectively obtained, so that a single-wavelength laser light can be emitted.
摘要:
A photonic crystal surface emission laser includes an active layer, and a photonic crystal layer made of a plate-shaped slab provided with modified refractive index area having a refractive index different from that of the slab, the modified refractive index areas being arranged on each of the lattice points of a first rhombic-like lattice and a second rhombic-like lattice in which both diagonals are mutually parallel and only one diagonal is of a different length, wherein ax1, ax2, ay, and n satisfy the following inequality: 1 a x 1 - 1 a x 2 ( 1 a x 1 + 1 a x 2 ) 2 + ( 2 a y ) 2 ≤ 1 n .
摘要:
The present invention intends to provide a surface-emitting laser light source using a two-dimensional photonic crystal in which the efficiency of extracting light in a direction perpendicular to the surface is high. In a laser light source provided with a two-dimensional photonic crystal layer created from a plate-shaped matrix body in which a large number of holes are periodically arranged and an active layer arranged on one side of the two-dimensional photonic crystal layer, the holes are created to be columnar with a predetermined cross-sectional shape such as a circular shape, and the main axis of each of the columnar holes is tilted to a surface of the matrix body. When provided with this two-dimensional photonic crystal layer, the surface-emitting laser source using a two-dimensional photonic crystal has a Q⊥ value (i.e. a Q value in a direction perpendicular to the surface) of several thousands, which is suitable for an oscillation of laser light, and the efficiency of extracting light is high in the direction perpendicular to the surface.
摘要:
The present invention provides a two-dimensional photonic crystal surface-emitting laser light source capable of producing a beam that is not accompanied by unnecessary side lobes. A window-shaped electrode 36 having a central window 361 devoid of the electrode material is provided on the surface of a device substrate 31 from which surface emission is extracted. A mount surface electrode 37 having an area smaller than that of the window-shaped electrode 36 including the window 361 is provided on a mount surface 38. The distance between the device substrate 31 and the active layer 32 is larger than that between the mount surface 38 and the active layer 32. When a voltage is applied between the electrodes, electric charges are injected into the active layer and emission is obtained. Then, a component of light having a specific wavelength is amplified by a two-dimensional photonic crystal 33, whereby a laser oscillation is produced. The laser light is extracted through the window 361 to the outside. Since the window-shaped electrode 36 does not block the emission of light, the emitted light never forms side lobes due to interference. The positioning of the active layer 32 close to the mount surface 38 significantly enhances the heat-radiating effect.
摘要:
A surface-emitting laser according to the present invention includes a laminated body between a first electrode 471 and a second electrode 472. The laminated body includes an active layer 43 and a two-dimensional photonic crystal 45. The first electrode 471 is ring shaped. A voltage is applied between the first and second electrodes 471 and 472 to supply an electric current into the active layer 43 and thereby cause an emission of light. Since the first electrode 471 is ring shaped, the light thereby generated has a ring-shaped field distribution within the two-dimensional photonic crystal 45. Due to this field distribution, a radially polarized laser beam having a ring-shaped cross section is emitted from the two-dimensional photonic crystal 45. The laser beam thus generated can be focused by a focusing lens to make its diameter smaller than the diffraction limit. Such a laser beam is suitable for optical pickups and other optical devices.
摘要:
A two-dimensional photonic crystal laser light is provided. The two-dimensional photonic crystal laser includes a two-dimensional photonic crystal made of a plate-shaped member provided with a periodic arrangement of identically-shaped modified refractive index areas having a refractive index different from that of the plate-shaped member; and an active layer provided on one side of the two-dimensional photonic crystal. The modified refractive index areas are arranged at lattice points of a lattice with a same period at least in two directions; each modified refractive index area is shaped so that a feedback strength is different with respect to directions of two primitive lattice vectors of the lattice; the two-dimensional photonic crystal has a periodic structure of a supercell, which contains a plurality of lattice points; and the sum of the feedback strengths by all modified refractive index areas in the supercell is identical in each direction of the two primitive lattice vectors.
摘要:
A two-dimensional photonic crystal laser light is provided. The two-dimensional photonic crystal laser includes a two-dimensional photonic crystal made of a plate-shaped member provided with a periodic arrangement of identically-shaped modified refractive index areas having a refractive index different from that of the plate-shaped member; and an active layer provided on one side of the two-dimensional photonic crystal. The modified refractive index areas are arranged at lattice points of a lattice with a same period at least in two directions; each modified refractive index area is shaped so that a feedback strength is different with respect to directions of two primitive lattice vectors of the lattice; the two-dimensional photonic crystal has a periodic structure of a supercell, which contains a plurality of lattice points; and the sum of the feedback strengths by all modified refractive index areas in the supercell is identical in each direction of the two primitive lattice vectors.
摘要:
A two-dimensional photonic crystal surface emitting laser light source according to the present invention includes a two-dimensional photonic crystal made of a plate-shaped body material provided with a periodic arrangement of identically-shaped holes 242A and an active layer provided on one side of the two-dimensional photonic crystal. The hole 242A is not located on a first half-line 251 extending from the gravity center G1 of the hole in a direction within the plane of the two-dimensional photonic crystal, while the hole 242A is located at least on a portion of a second half-line 252 extending from the gravity center G1 in the direction opposite to the first half-line 251. Injecting electric charges into the active layer generates light, which creates an electric field that encircles the gravity center G1 within the two-dimensional photonic crystal. For a given point on the second half-line 252 at which the hole 242A is located, there is no hole at a point that is symmetrical to the aforementioned point with respect to the gravity center G1, so that there is a difference in the refractive index between the two points. Thus, the electric field vectors at the two points are prevented from canceling each other due to destructive interference, so that the resultant laser light is stronger than conventional examples.
摘要:
An objective of the present invention is to provide a laser capable of producing a radially polarized laser beam with an annular cross section. A laser oscillator 60 including an active layer 53 and two-dimensional photonic crystal 55 with circular holes 552 arranged in a square lattice pattern is provided between two electrodes 571 and 572. A first polarization control layer 581, which functions as a half-wave plate, and a second polarization control layer 582, which functions as a half-wave plate with a fast axis 592 extending at an angle of 45° to that of the first polarization control layer 581, are located on the laser oscillator 60. When a voltage is applied between the electrodes, a circumferentially polarized annular laser beam is emitted from the laser oscillator 60. When passing through the first polarization control layer 581 and the second polarization control layer 582, the laser beam is converted to a radially polarized beam. The resultant laser beam can be converged by a focusing lens to achieve a diameter smaller than the diffraction limit. Such a narrow beam is suitable for an optical pickup or many other devices.