# US 5,347,394 A · Nonlinear optical materials, method of manufacturing the same, and optical wavelength converter

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- Number: US 5,347,394 A
- Document ID: US5347394A
- Status: Granted
- Kind: A
- Application number: 08/043,407
- Filed: 1993-04-06
- Granted: 1994-09-13
- Earliest claimed: 1992-06-05
- Assignees: Matsushita Electric Industrial Co., Ltd.
- Inventors: Katsuya Wakita; Tetsuji Kawakami; Nobuo Sonoda; Hisashi Minemoto
- Web page: https://patentgrep.com/patent/US5347394A

## CPC

- G02F 1/361: Organic materials
- G02F 1/3611: {containing Nitrogen}
- G02F 1/3613: {containing Sulfur}
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS

## Abstract

The invention provides a nonlinear optical material comprising a compound represented by the general formula (1): ##STR1## wherein R.sup.1 denotes an electron attractive group, R.sup.2 denotes a group selected from the group consisting of a hydrogen atom, methyl group, methoxy group and electron attractive group, R.sup.3 denotes a straight-chain alkylene group, and X denotes an oxygen or sulfur atom. The invention also relates to a method of manufacturing a nonlinear optical material comprising the steps of dissolving a compound represented by the general formula (1) in an organic solvent, and evaporating the solvent while keeping its temperature constant or lowering its temperature, thereby growing a crystal of the compound represented by the general formula (1). The nonlinear optical material of the invention possessing a molecular structure realized by linking structures having a strong electron attractive group and weak electron donative portion with straight-chain alkylene portions, and thus a nonlinear optical material having a shortened absorption edge wavelength and excellent crystallinity may be obtained. These nonlinear optical materials can be effectively utilized as the nonlinear optical material for an optical wavelength converter.

## Claims

### Claim 1

A wavelength converter which is disposed in an optical resonator of a laser apparatus comprising a semiconductor laser, solid state laser medium and optical resonator, or which is disposed in an optical resonator of a laser apparatus comprising a semiconductor laser and an optical resonator, in which the nonlinear optical material of the wavelength converter comprises a compound represented by the general formula (1) ##STR21## wherein R.sup.1 denotes an electron attractive group, R.sup.2 denotes a group selected from the group consisting of a hydrogen atom, methyl group, methoxy group and electron attractive group, R.sup.3 denotes a straight-chain alkylene group, and X denotes an oxygen or sulfur atom.

### Claim 2

A wavelength converter of an optical waveguide type of which nonlinear optical material of the waveguide for propagating the fundamental wave comprises a compound represented by the general formula (1) ##STR22## wherein R.sup.1 denotes an electron attractive group, R.sup.2 denotes a group selected from the group consisting of a hydrogen atom, methyl group, methoxy group and electron attractive group, R.sup.3 denotes a straight-chain alkylene group, and X denotes an oxygen or sulfur atom.

### Claim 3

A method of manufacturing a nonlinear optical material comprising the steps of dissolving a compound represented by the general formula (1) in an organic solvent, and evaporating said solvent while keeping its temperature constant or lowering its temperate, thereby growing a crystal of the compound represented by the general formula (1) ##STR23## wherein R.sup.1 denotes an electron attractive group, R.sup.2 denotes a group selected from the group consisting of a hydrogen atom, methyl group, methoxy group and electron attractive group, R.sup.3 denotes a straight-chain alkylene group, and X denotes an oxygen or sulfur atom.

### Claim 4 (depends on 3)

The method of manufacturing a nonlinear optical material according to claim 3, wherein the organic solvent is at least one organic solvent selected from the group consisting of acetone, toluene, chloroform and tetrahydrofurane.

### Claim 5 (depends on 3)

The method of manufacturing a nonlinear optical material according to claim 3, wherein the rate of evaporation of the organic solvent is 100 ml/day or less.