Phase-Matched Wavelenght-Conversion in Nonlinear-Optical Waveguide of Organic Crystal Based on Thickness Control of LB Film

基于LB膜厚度控制的有机晶体非线性光波导相位匹配波长转换

• 批准号: 06452135
• 负责人: UMEGAKI Shinsuke
• 金额: $ 3.9万
• 依托单位: Keio University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06452135/
• 关键词: Langmuir-Blodgett Film; Second-harmonic generation; Nonlinear optics; Organic materials; Planar waveguides; N-dococyl-N^1- (4-nitrophenyl) urea

We studied Langmuir-Blodgett (LB) films in a viewpoint of thickness control of top layrs on guideing layrs of organic nonlinear-optical crystals. The LB film as a top layr can be stacked layr by layr and the thickness can be precisely controlled, since, generally, on LB layr has thickness of nm-order. In the research, by means of stacking LB layrs, we experimentally achieved optical second-harmonic generation (SHG) under the condition of thickness-controlled phase-matching with practcally large tolerance and theoretically designed how to obtain larger tolerance in guided-to-guided mode SHG for given thickness of the guiding layre.In the experiment, we tried to stack Z-type LB layrs of N-dococyl-N^1- (4-nitrophenyl) urea (DONPU) on the inorganic nonlinear-optical LiTaO_3 epitaxially grown on the inorganic LiNbO_3 substrate. As a result, we could attain SHG under the tolerable phase-matching within a thickness range of 45 nm of the LiTaO_3 layr, which is wide enough in comparison with the usual thickness range of 1 nm-order. We also found that the stearic acid has to be used as the intermediate layr on the LiTaO_3, since DONPU can be stacked on the hydrophobic substrate.In the theory, we treated the organic nonlinear-optical (-) 2- (alpha-methylbenzylamino) -5-nitrophyridine (MBANP) and 3,5-dimethyl-1- (4-nitrophenyl) pyrazole (DMNP) as the guiding layrs on the glass substrates with the appropriate buffer layrs. We could predict that the wide thickness-range of the guiding layr can provide the tolerably phase-matched SHG,where the phase matching is controlled by stacking the DONP film layr by layr according to the thickness of the guiding layr.

本文从有机非线性光学晶体导层顶层厚度控制的角度研究了Langmuir-Blodgett （LB）薄膜。LB膜作为顶层，可以逐层堆叠，厚度可以精确控制，因为LB膜的厚度一般为nm级。在本研究中，通过LB层的叠加，实验实现了在厚度控制相位匹配条件下具有较大容差的光学二次谐波产生，并从理论上设计了在给定导层厚度下导-导模式二次谐波产生的较大容差。在实验中，我们尝试在无机LiNbO_3衬底外延生长的无机非线性光学LiTaO_3上堆叠N-dococyl-N^1-（4-硝基苯基）尿素（DONPU）的z型LB层。结果表明，在容许相位匹配的情况下，我们可以在45 nm的LiTaO_3层厚度范围内实现SHG，这与通常的1 nm级厚度范围相比是足够宽的。我们还发现硬脂酸必须用作LiTaO_3的中间层，因为DONPU可以堆叠在疏水性衬底上。在理论上，我们将有机非线性光学（-）2- （α -甲基苄基氨基）-5-硝基吡啶（MBANP）和3,5-二甲基-1-（4-硝基苯基）吡唑（DMNP）作为引导层，并在玻璃衬底上设置适当的缓冲层。我们可以预测，较宽的导层厚度范围可以提供可容忍的相位匹配SHG，其中相位匹配是通过根据导层厚度逐层堆叠DONP膜来控制的。

项目成果

H. Yamamoto 他5名: "A Four Layer Optical Waveguide Device Using Isopropyl-4-Acetylphenylurea (IAPU)" Nonlinear Opt.14. 263-272 (1995)

H. Yamamoto 和其他 5 人：“使用异丙基-4-乙酰基苯基脲 (IAPU) 的四层光波导器件”非线性 Opt.14 (1995)。

S.-T.Ko 他2名: "Crystal Growth of Large-Area Thin Films of 2-Methyl-4-Nitroaniline for Quasi-Phase-Matched Second-Harmonic Generation" Nonlinear Opt.15. 197-204 (1996)

S.-T.Ko 和其他 2 人：“用于准相位匹配二次谐波生成的大面积 2-甲基-4-硝基苯胺薄膜的晶体生长”非线性 Opt.197-204 (1996)。

T. Sassa and S. Umegaki: "Design of Optical Waveguide for SHG with Efficiently Enlarged Tolerance of Waveguide Thickness for Guided-to-Guided Mode Phase-Matching" to be submitted to Opt. Rev.

T. Sassa 和 S. Umegaki：“SHG 光波导设计，有效扩大波导厚度公差，实现导模相位匹配”，提交至 Opt。

S. Yamakawa 他5名: "Frequency Doubling Waveguide on a Novel Organic Nonlinear Optical Structure" Nonlinear Opt.14. 273-281 (1995)

S. Yamakawa 和其他 5 人：“新型有机非线性光学结构上的倍频波导”非线性 Opt.14 (1995)。

E.S.Kim: "Optical Second-Harmonic Generation by a Novel Waveguide Device with Nonlinear Organic Crystal" O puls E. No.186. 83-90 (1995)

E.S.Kim：“采用非线性有机晶体的新型波导装置产生光学二次谐波”O puls E. No.186。