Japan Science and Technology Agency

Japan Science and Technology Corporation

Hoya Corporation

Kenichi Kawamura

Hideo Hosono

Masahiro Hirano

Nobuhiko Sarukura

Masahiro Orita

Hiromichi Ota

Taisuke Miura

Hayato Kamioka

Msahiro Hirano

Disclosed is a method of producing a hologram through a two-beam laser interfering exposure process, which comprises emitting a coherent laser light with a pulse width (&#x3c4;) ranging from greater than 900 femtoseconds to 100 picoseconds and a laser power of 10 &#x3bc;J/pulse or more using a solid-state laser as a light source, dividing the pulses light from the laser into two beams, controlling the two beams temporally and spatially in such a manner that the two beam are converged on a surface of or inside a workpiece for recording a hologram while matching the respective converged spots of the two beams with one another temporally and spatially to create the interference therebetween so as to record a surface-relief hologram on the surface of the workpiece or an embedded hologram inside the workpiece in an irreversible manner. The present invention can solve a problem with a conventional process of recording a hologram in a non-photosensitive material in an irreversible manner using interfering femtosecond laser pulses, specifically, distortion in the waveforms of pulsed laser beams and resulting instability in recording of an embedded hologram due to a non-linear optical interaction between the femtosecond laser pulses and air/the material.

Method for producing hologram by pico-second laser

An ultraviolet-light-emitting semiconductor diode comprising an n-type ZnO layer with luminous characteristics formed on a transparent substrate, and a p-type semiconductor layer selected from the group consisting of SrCu O , CuAlO and CuGaO , which is formed on the n-type ZnO layer to provide a p-n junction therebetween. The transparent substrate is preferably a single crystal substrate having atomically flat yttria-stabilized zirconia (YSZ) (III) surface. The n-type ZnO layer is formed on the transparent substrate having a temperature of 200 to 1200&deg; C., and the p-type semiconductor layer selected from the group of SrCu O , CuAlO and CuGaO is formed on the n-type ZnO layer. The n-type ZnO layer may be formed without heating the substrate, and then the surface of the ZnO layer may be irradiated with ultraviolet light to promote crystallization therein.

Light-emitting diode and laser diode having n-type ZnO layer and p-type semiconductor laser

A method and apparatus for producing a hologram using a two-beam laser interference exposure process, comprising the steps of using as a light source a femtosecond laser having a pulse width of 900-10 femtoseconds and a peak output of 1 GW or more and capable of generating a pulse beam at or close to the Fourier transform limit, dividing the pulse beam from the laser into two by a beam splitter, controlling the two beams temporally through an optical delay circuit and spatially using plane and concave mirrors each having a slightly rotatable reflection surface to converge the beams on a surface of or within a substrate for recording a hologram at an energy density of 100 GW/cm or more with keeping each polarization plane of the two beams in parallel so as to match the converged spot of the two beams temporally and spatially, whereby a hologram is recorded irreversibly on the substrate formed of a transparent material, semiconductor material or metallic material.

Production method and device for hologram

Growing community of inventors

Sagamihara, Japan

Kenichi Kawamura