매우 높은 오프-다이아고날 비선형 광학 특성을 가진 플루오르화 벤조사이아졸리움 기반의 유기 결정
new fluorinated benzothiazolium-based organic crystals with extremely large off-diagonal optical nonlinearity
- 주제(키워드) 비선형광학 , 테라헤르츠
- 발행기관 아주대학교
- 지도교수 권오필
- 발행년도 2019
- 학위수여년월 2019. 2
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000028387
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
For various application of nonlinear optics, π-conjugated organic materials have to exhibit large macroscopic diagonal and off-diagonal nonlinear optical response in crystalline state. We designed new organic ionic crystals consisting of fluorinated benzothiazolium based PM5FB (5-fluoro-2-(4-(4-(hydroxymethyl)piperidin-1-yl)styryl-3-methylbenzo[d]thiazol-3-ium) cation and various counter anions. We observed that PM5FB based chromophores have high thermal stability and microscopic optical nonlinearity. All of PM5FB based organic crystals have isomorphic series-type crystal structure formed by hydrogen bonding between cation and anion which is similar to previously reported PMB-T (2-(4-(4-(hydroxymethyl)piperidin-1-yl)styryl-3-methylbenzo[d]thiazol-3-ium 4-methylsulfonate) crystal. Surprisingly, it was investigated that PM5FB-CBS (5-fluoro-2-(4-(4-(hydroxymethyl)piperidin-1-yl)styryl-3-methylbenzo[d]thiazol-3-ium 4-chlorobenzenesulfonate) has molecular ordering of 56.7° which is very close to optimal angle for maximizing off-diagonal component. In THz generation experiment, off-diagonal term of PM5FB-CBS crystal shows a 3 times more efficient peak-to-peak THz electric field than diagonal term of standard inorganic ZnTe crystal and reduced dimples in the THz wave spectra which indicate that phonon mode was suppressed.
more목차
1. Introduction 1
2. Experiments 5
3. Results and Discussion 18
4. Conclusions 41
5. References 42
