• Title/Summary/Keyword: Nonlinear optical materials

Search Result 90, Processing Time 0.041 seconds

Periodically poled stoichiometric lithium tantalate for optical parametric oscillation (주기적으로 분극반전된 stoichiometric $LiTaO_3$ 이용한 광매게발생)

  • Lee, Yu-Nan;Sunao Kurimuyn;Masaru Nakamura;Kenii Kitamura
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 2003.02a
    • /
    • pp.228-229
    • /
    • 2003
  • The quasi-phase matching (QPM) technique has dramatically changed the guidelines in developing nonlinear optical materials, which doesn't require birefringence and off-diagonal components for efficient wavelength conversion. Minimum requirement for QPM is the modulation of nonlinearity and ferroelectric materials with low coercive field has become fascinating in periodical poling. Stoichiometric lithium tantalate (SLT) has attractive advantages of low coercive field (∼l .5 KV/mm), high nonlinearity, high optical damage resistance and low thermo-optic coefficients, leading to a large aperture QPM devices for high power operation. (omitted)

  • PDF

졸-겔법에 의한 CdS 분산$SiO_2$ Glass 박막의 비선형광학특성

  • 문종수;강종봉;김경문
    • Journal of the Korean Ceramic Society
    • /
    • v.33 no.12
    • /
    • pp.1353-1364
    • /
    • 1996
  • Recently semiconductor doped glasses have attracted attention as nonlinear optical materials because of their large third order nonlinear optical properties. The transparent and homogeneous CdS-doped SiO2 glass thin films were obtained by the dip=coating process of the sol-gel method. Thin films were consisted of glasses containing CdS microcrystallites which were formed by dissolved Cd2+ and S2- ions in a SiO2 matrix solutions. A subsequent thermal treatment of this samples led the formation of colloidal agglomerates and finally of microcrystallites. The size of CdS microcrystallites was about 4 to 15 nm after thermal treatments at various heating conditions. From the optical absorption spectra of the CdS-doped SiO2 glass films it was found that the absorption edge was blue-shifted compared with that of the bulk CdS crystal(~2, 4 eV) and that the amount of energy shift was inversely proportional to the crystal size. And the band gap energy increased with the decrease in crystallite size indicating that the quantum size effects occured.

  • PDF

Semiconductor nonlinear optical spectroscopy (반도체의 비선형 분광학)

  • 박승한
    • Korean Journal of Optics and Photonics
    • /
    • v.3 no.4
    • /
    • pp.280-287
    • /
    • 1992
  • The nonlinear optical properties of semiconductors and semiconductor microstructures have been the subject of intense research, not only from a fundamental physics point of view, but also for their potential applications to future opto-electronic devices. In this paper, steady-state and time-resolved nonlinear optical spectroscopic techniques to investigate the microscopic world of semiconductor materials were briefly described.

  • PDF

Nonlinear absorption in charge transfer films

  • Cha, M.;Sariciftici, N.S.;Heeger, A.J.;Hummelen, J.C.;WudI, F.
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 1995.06a
    • /
    • pp.161-168
    • /
    • 1995
  • Nonlinear optical absorption in solid films of poly(3-octyl thiophene) (P3OT) sensitized with methanofullerene was inverstigated for wacelengths from 620 to 960nm. The nonlinear absorption is ehnanced over that in either of the component materials by more than two orders orders of magitude at 760nm. The large nonlinearity results from effient photoinduced interm olecular charge transfer from P3OT to methanofullerene, followed by absorption in the charge separated excited state. P3OT/fullerene films are promising as reverse saturable absorbers and the optical limiting performance is demonstrated at 760nm.

  • PDF

Second Order Nonlinear Optical Polyimides Containing Organic Chromophores with an Oxadiazole Segment (옥사디아졸 결합의 유기 발색단이 도입된 이차비선형 광학 이미드 고분자)

  • Do, Jung Yun;Kim, Bong Gun;Kwon, Ji-Yun
    • Applied Chemistry for Engineering
    • /
    • v.18 no.1
    • /
    • pp.77-83
    • /
    • 2007
  • It is essential that second order nonlinear optical materials have low optical propagation losses in the wavelengths of second harmonic generation for practical applications in waveguides. Three dipolar chromophores substituted with nitro, cyano, and alkyl sulfone as an electron withdrawing group were prepared. The UV-Vis absorption spectra of the cyano and alkylsulfone chromophores showed a blue-shift compared to the nitro chromophore. The introduction of oxadiazole segment in the chromophore structure led to similar spectral shift. The blue-shift can produce low optical loses at second harmonics. The chromophores were successfully attached to a polyimide, yielding side chain polymers. The nonlinear optical property of the prepared optical polymers was determined by measuring electro-optic coefficient at 1.55 mm. The polymers exhibited high glass transition temperature of over $185^{\circ}C$ and thermal stability to $300^{\circ}C$ through differential scanning calorimeter analysis and thermal gravimetric analysis.