2차 비선형 광특성의 제어를 위한 실리카 유리의 전기분극 기구 전산모사

유웅현; 이승규; 신동욱; 정용재; Woong Hyun Ryu; Seung Kyu Lee; Dong Wook Shin; Yong-Chae Chung

Korean Journal of Materials Research, Vol.11, No.3, 207-214, March, 2001

Export Citation

2차 비선형 광특성의 제어를 위한 실리카 유리의 전기분극 기구 전산모사

Computer Simulation on the Poling Mechanism for the Control of 2nd Order Optical Nonlinearity in Silica Glass

유웅현, 이승규, 신동욱, 정용재

한양대학교 세라믹공학과

Woong Hyun Ryu, Seung Kyu Lee, Dong Wook Shin, and Yong-Chae Chung

Dept. of Ceramic Engineering, Hanyang University, Seoul, 133-791, Korea

초록

실리카 유리는 매우 우수한 광도파 소재이지만 비선형 광특성이 거의 없다. 그러나 이런 실리카 유리에 금속 전극과 같은 차단전극을 이용하여 강한 전기장을 장시간 가하게 되면 공간 전하 분극이 발생하게 되고 이에 의해 비선형 광특성이 나타나게 된다는 것은 실험적으로 알려져 왔다. 본 연구에서는 전기분극 시 실리카 유리에서 나타나는 비선형 광특성의 경시적인 변화를 공간적인 위치와 시간에 따라 정확히 예측할 수 있는 수치해석적인 모델을 제시하고자 하였다. 이를 위해서 지금가지 실험들에서 실리카 유리의 비선형 광특성 발생의 원인으로 밝혀진 공간전하분극을 전기분극 기구의 전산모사를 통하여 규명하였다. 비정질 실리카를 전해질 용액과 같은 특성을 지니는 매질로 가정하고 전하운반체가 단지 Na + 밖에 없다는 가정 하에 유한 차분법 (finite difference method)을 이용하였다. 원래의 복잡한 함수들을 표준화 변수들을 이용하여 간단한 식으로 변환하여 Na + 의 농도와 전기장의 분포를 표준화된 시편의 길이와 인가된 전압의 세기만으로 구할 수 있도록 하였다.

Silica glass is a core material for optical fiber in optical telecommunications, but its centrosymmetry eliminates the second order nonlinearity. But it is experimentally well known that the space charge polarization induces the Second Harmonic Generation (SHG) when a strong DC voltage is applied to silica glass for a long period of time with metal blocking electrodes. In this report, the results of a theoretical calculation of the nonlinear optical property caused by the space charge polarization, and a model of a numerical analysis to predict the small chance in nonlinear optical property as functions of time and space are provided. Assuming that amorphous silica is a solid state electrolyte and sodium ion is the only mobile charge carrier, 'Finite Difference Method' was employed for modeling of numerical analysis. The distributions of the concentration of sodium ion and electric field as functions of a normalized length of the specimen and a normalized applied voltage were simulated.

Keywords:optical switch;silica;poling;SHG

[References]

Myers RA, Mukherjee N, Brueck SRJ, Opt. Lett., Large second order nonlinearities in poled fused silica, 16, 1732 (1991)
Kazansky PG, Russell PSJ, Takebe H, J. Lightwave Technol., Glass fiber poling and applications, 15(8), 1484 (1997)
Nye JF, Physical Properties of Crystals, Oxford University Press, 241 (1967) (1967)
Kazansky PG, Smith AR, Russell PSJ, Yang GM, Sessler GM, Appl. Phys. Lett., Thermally poled silica glass: Laser induced pressure pulse probe of charge distribution, 68, 269 (1996)
Takebe H, Kazansky PG, Russell PSJ, Morinaga K, Opt. Lett., Effect of poling conditions on second harmonic generation in fused silica, 20, 468 (1996)
신동욱, 한국요업학회지, 실리카 유리의 전기이완 특성과 비선형적 전기전도도, 36(9) (1999)
Mukherjee N, Myers RA, Brueck SRJ, J. Opt. Soc. Amer. B, Dynamics of second harmonic generation in fused silica, 11, 665 (1994)
Owen AE, Douglas RW, J. Soc. Glass Tech., The Electrical Properties of Vitreous Silica, 43, 159 (1959)
Shin DW, Tomozawa M, J. Non-Cryst. Solids, The Electrical Resistivity of Silica Glasses, 163, 203 (1993)
Doremus RH, 'Glass Science', 2nd ed., John Wiley & Sons Inc., (1994) (1994)
Myers RA, Long X, Brueck SRJ, 'Recent advances in the second-order nonlinear optical properties of amorphous silica materials,' SPIE Vol. 2289 Doped Fiber Devices and Systems (1994) (1994)
Alley TG, Brueck SRJ, Myers RA, J. Non-Cryst. Solids, Space charge dynamics in thermally poled fused silica, 242, 165 (1998)
Beaumont JH, Jacobs PW, J. Phys. Chem. Solids, Polarization in Potassium Chloride crystals, 28, 657 (1967)
Proctor TM, Sutton PM, J. Amer. Ceram. Soc., Space Charge Development in Glass, 43(4), 173 (1960)
Alley TG, Brueck SRJ, Myers RA, J. Non-Cryst. Solides, Space charge dynamics in thermally poled fused silica, 242, 165 (1998)
Shin DW, Tomozawa M, J. Non-Cryst. Solides, Electrical and dielectric relaxation in silica glasses at low temperature, 211, 237 (1997)
Chung YC, 'Toward the Measurement of Reliable Grain-Boundary Diffusion Coefficients in Oxides', Ph.D. Thesis, M.I.T., USA, 1995 (1995)
Burden RL, Faires JD, 'Numerical Analysis,' 5th Ed., p. 635-646, PWS PUBLISHING COMPANY, Boston, 1993 (1993)
Raabe D, 'Computational Materials Science', p. 38, Wiley-VCH, Weinheim, 1998 (1998)

[1] Myers RA, Mukherjee N, Brueck SRJ, Opt. Lett., Large second order nonlinearities in poled fused silica, 16, 1732 (1991)

[2] Kazansky PG, Russell PSJ, Takebe H, J. Lightwave Technol., Glass fiber poling and applications, 15(8), 1484 (1997)

[3] Nye JF, Physical Properties of Crystals, Oxford University Press, 241 (1967) (1967)

[4] Kazansky PG, Smith AR, Russell PSJ, Yang GM, Sessler GM, Appl. Phys. Lett., Thermally poled silica glass: Laser induced pressure pulse probe of charge distribution, 68, 269 (1996)

[5] Takebe H, Kazansky PG, Russell PSJ, Morinaga K, Opt. Lett., Effect of poling conditions on second harmonic generation in fused silica, 20, 468 (1996)

[6] 신동욱, 한국요업학회지, 실리카 유리의 전기이완 특성과 비선형적 전기전도도, 36(9) (1999)

[7] Mukherjee N, Myers RA, Brueck SRJ, J. Opt. Soc. Amer. B, Dynamics of second harmonic generation in fused silica, 11, 665 (1994)

[8] Owen AE, Douglas RW, J. Soc. Glass Tech., The Electrical Properties of Vitreous Silica, 43, 159 (1959)

[9] Shin DW, Tomozawa M, J. Non-Cryst. Solids, The Electrical Resistivity of Silica Glasses, 163, 203 (1993)

[10] Doremus RH, 'Glass Science', 2nd ed., John Wiley & Sons Inc., (1994) (1994)

[11] Myers RA, Long X, Brueck SRJ, 'Recent advances in the second-order nonlinear optical properties of amorphous silica materials,' SPIE Vol. 2289 Doped Fiber Devices and Systems (1994) (1994)

[12] Alley TG, Brueck SRJ, Myers RA, J. Non-Cryst. Solids, Space charge dynamics in thermally poled fused silica, 242, 165 (1998)

[13] Beaumont JH, Jacobs PW, J. Phys. Chem. Solids, Polarization in Potassium Chloride crystals, 28, 657 (1967)

[14] Proctor TM, Sutton PM, J. Amer. Ceram. Soc., Space Charge Development in Glass, 43(4), 173 (1960)

[15] Alley TG, Brueck SRJ, Myers RA, J. Non-Cryst. Solides, Space charge dynamics in thermally poled fused silica, 242, 165 (1998)

[16] Shin DW, Tomozawa M, J. Non-Cryst. Solides, Electrical and dielectric relaxation in silica glasses at low temperature, 211, 237 (1997)

[17] Chung YC, 'Toward the Measurement of Reliable Grain-Boundary Diffusion Coefficients in Oxides', Ph.D. Thesis, M.I.T., USA, 1995 (1995)

[18] Burden RL, Faires JD, 'Numerical Analysis,' 5th Ed., p. 635-646, PWS PUBLISHING COMPANY, Boston, 1993 (1993)

[19] Raabe D, 'Computational Materials Science', p. 38, Wiley-VCH, Weinheim, 1998 (1998)