Dainippon Screen Mfg. Co., Ltd.

Mitsubishi Denki Kabushiki Kaisha

Screen Holdings Co., Ltd.

Osaka University

Toshiaki Suhara

Masahide Okazaki

Natsuro Tsubouchi

Shiro Hine

Mitsushige Kondou

Keizo Kono

Hiroshi Nishihara

A first electro-optic crystal substrate and a second electro-optic crystal substrate are provided as an electro-optic crystal substrate. The first electro-optic crystal substrate comprises a first periodic polarization reversal structure in which first polarization pairs, in each of which the directions of polarization in response to electric fields are opposite to each other, are arranged in a first period along a first arrangement direction which is orthogonal or inclined with respect to the direction of propagation, and light passes through the first periodic polarization reversal structure. The second electro-optic crystal substrate comprises a second periodic polarization reversal structure in which second polarization pairs, in each of which the directions of polarization in response to electric fields are opposite to each other, are arranged in a second period along a second arrangement direction which is orthogonal or inclined with respect to the direction of propagation, and light outstanding from the first electro-optic crystal substrate passes through the second periodic polarization reversal structure. At least one of a first condition and a second condition is satisfied. The first condition is that the first and the second periods are different from each other and a second condition is that the first arrangement direction and the second arrangement direction are different from each other.

Light modulator and exposure head

The ferroelectric substrateof ferroelectric crystals, while being supported by the support platewhich is thicker than the ferroelectric substrate, is integrated with the support plateby letting the junctionmediate between one major surface SA of the ferroelectric substrateand one major surface SB of the support plate, and therefore, it is possible through the flat surface polishing to perform thinning of the ferroelectric substrate, namely, the ferroelectric crystals, and as a result, it is possible to obtain the thin periodically poled structure. By the voltage application method, the domain inverted region is formed in the ferroelectric substratewhich is made thin.

Optical device, a method of manufacturing optical device, and exposure apparatus

As a spatial light modulatoris disposed between a wavelength conversion partand an exit surfacein a ferroelectric crystal substrate, only zeroth-order light which is at a particular wavelength is guided to a substrate while laser light from the wavelength conversion partis being modulated, whereby a pattern corresponding to LSI data is drawn. Further, the spatial light modulatoris disposed together with the wavelength conversion partsandinside the ferroelectric crystal substrate

Optical device, exposure apparatus and laser apparatus

In an optical modulator, a first electrode portion having a plurality of first electrodes is provided on the upper surface of a base part having a periodically-poled structure and a second electrode portion is provided on the lower surface thereof, and voltage is applied in one direction between the first electrode portion and the second electrode portion, to thereby cause a periodic change of the refractive index in a polarization-part array direction in the periodically-poled structure and diffract light which enters the base part. This allows reduction in the voltage applied between the first electrode portion and the second electrode portion, and it is thereby possible to form a desired electric field inside the periodically-poled structure while achieving a high-density channel arrangement. By reducing the voltage, the rate of the optical modulation performed by the optical modulator can be increased.

Optical modulator

An optical IC-type head assembly for recording and for reading information on an optical disc, comprising a substrate, a light guiding layer comprising a dielectric thin film formed monolithically on the substrate, a laser oscillator for injecting the laser beam into the light guiding layer, a grating coupler for converging the laser beam on the optical disc, and a photo detector for receiving the beam reflected by the optical disc and coming out of the grating coupler. In one embodiment the substrate is made of material having cleavability. One side surface of the light guiding layer receiving the laser beam is a break surface formed by cleaving the substrate along the cleavage plane. The photo detector is disposed at the break surface of the light guiding layer. The substrate is preferably made of single crystal material. In another embodiment, a beam splitter is disposed between the laser oscillator and the grating coupler for splitting the reflected beam coming out of the grating coupler into two symmetrical beams. Each split beam forms an acute angle with respect to the optical axis of the reflected beam. The acute angle is preferably less than 30 degrees. The beam splitter may converge each of the split beams at a photo detecting element disposed between the laser oscillator and the grating coupler.

Growing community of inventors

Osaka, Japan

Toshiaki Suhara