محاسبه ضرایب شکست، ضرایب جذب و پذیرفتاری مرتبه سوم در مخلوط بلورمایع نماتیک 5CB و نانوذرات zns

نویسندگان

1 گروه فیزیک، دانشکده علوم پایه، دانشگاه نیشابور، شهر نیشابور، استان خراسان رضوی

2 گروه فیزیک، دانشکده علوم پایه، دانشگاه تربیت دبیر شهیدرجایی، تهران، استان تهران

چکیده

در این پژوهش، پذیرفتاری مرتبه سوم نانوذرات ZnS که در بلورمایع نماتیک 5CB آلاییده شده مورد بررسی و آنالیز قرار گرفته است. ابتدا نانوذرات ZnS به‌روش هیدروترمال تهیه شدند. سپس این نانوذرات با درصد وزنی wt. 1 به بلورمایع نماتیک اضافه شد. بعد از آن، برای محاسبه پذیرفتاری مرتبه سوم، ضرایب جذب خطی و غیرخطی و ضرایب شکست خطی و غیرخطی به دست آمد. منبع نور مورد استفاده در این تحقیق، لیزر پیوسته هلیوم نئون با طول موج nm 632.8 می‌باشد. جهت‌گیری اولیه ملکول‌ها عمودی است. نتایج نشان می‌دهد که پدیده‌های غیرخطی خودواگرایی و جذب دو فوتونی در نمونه رخ داده است. با توجه به نتایج بدست آمده ضریب شکست غیرخطی و ضریب جذب غیرخطی بلور مایع نماتیک 5CB به همراه نانوذرات ZnS به ترتیب 5 و 3 برابر ضریب شکست و ضریب جذب غیرخطی بلور مایع نماتیک 5CB خالص می باشد.

کلیدواژه‌ها


عنوان مقاله [English]

Calculating ofthe Refractive index,the absorption and the third order susceptibility coefficientsin the nematic liquid crystal 5CBandZnS nanoparticles complex

نویسندگان [English]

  • Z. Dehghani 1
  • M. Nadafan 2
  • A. Faraji Alamooti 1
1 Department of Physics, Faculty of Science, University of Neyshabur, Neyshabur
2 Department of Physics, Faculty of Science, Shahid Rajaee Teacher Training University, Tehran
چکیده [English]

In this research, third order nonlinear susceptibility of ZnS nanoparticles NPs in nematic liquid crystals NLCs have been recorded and analyzed. ZnS NPs have been synthesized by the hydrothermal method. Afterwards, the nonlinear refractive NLR index, linear refraction index , nonlinear absorption NLA coefficient, linear absorption coefficient and third order nonlinear susceptibility, of pure NLCs and ZnS NPs in NLCs were measured using the z-scan technique by using a continues wave CW He: Ne laser at 632.8 nm wavelength. The measurements were performed for homeotropic initial alignments of NLCs molecules. Strong optical nonlinearity, self-defocusing and two photon absorption TPA effects are observed for pure NLCs and ZnS NPs in NLCs by homeotropic alignments. according to given results, the NLR index and the NLA coefficient of the 5CB NLCs doped by ZnS NPs five and three times of the NLR and the NLA coefficient of pure NLCs, respectively.

کلیدواژه‌ها [English]

  • Nematic liquid crystals
  • ZnS nanoparticles
  • refraction index
  • adsorption coefficient
  • Nonlinear Optical properties
  • Third order nonlinear susceptibility
  • Z-scan technique
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