1995 Fiscal Year Final Research Report Summary
Study of third-order optical nonlinear devices using semiconductor microcrystals
| Project/Area Number |
06650049
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Applied optics/Quantum optical engineering
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
MIZUMOTO Tetsuya Tokyo Inst.of Tech., Faculty of Eng., Assoc.Professor, 工学部, 助教授 (00174045)
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| Co-Investigator(Kenkyū-buntansha) |
YOKOI Hideki Tokyo Inst.of Tech., Faculty of Eng., Research Assoc., 工学部, 助手 (90251636)
ANZAI Hiroki Tokyo Inst.of Tech., Faculty of Eng., Research Assoc., 工学部, 助手 (80212661)
NAITO Yoshiyuki Tokyo Inst.of Tech., Faculty of Eng., Professor, 工学部, 教授 (70016335)
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| Project Period (FY) |
1994 – 1995
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| Keywords | third-order optical nonlinear effect / semiconductor microcrystal / semiconductor-doped glass / resonant wavelength / photon-electron interaction / optical resonator / optical switch / nonlinear directional coupler |
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| Research Abstract |
The purpose of this study is to investigate the enhancement of third-order optical nonlinearity in CdS_xSe_<1-x> doped glass and to demonstrate its effectiveness for constructing optical functional devices. In this study, third-order nonlinear susceptibility observed at a signal wavelength is examined in the CdS_xSe_<1-x> doped glass pumped by light of different wavelength.
We calculated the third-order nonlinear susceptibility using a density matrix method with rotating wave approximation. The distributions of microcrystal size and composition are taken into account in the calculation. It is shown that, comparing to the case of being pumped at the signal wavelength, which is longer that the band gap wavelength, larger intensity dependent refractive index change, typically by a factor of 10^3, is obtained when being pumped at the wavelength close to the band gap. A figure of merit of the material under consideration is discussed considering the nonlinear absorption, which is associated with the imaginary part of nonlinear susceptibility.
The large refractive index change obtained at low absorption wavelength region gives us flexibility in designing a variety of all-optical functional devices. We designed the optical gate switch controlled with pump beam close to band gap and showed its ellectiveness. It is shown that the switching energy can be remarkably reduced. Also, the signal lightwave can be controlled with the pump light of which intensity is lower than that of the signal light.
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