Optical limiters nonlinear photonic materials

Nanostructured Polymeric Nonlinear Photonic Materials for Optical Limiting... 

Nonlinear optical organic materials such as porphyrins, dyes, and phthalocyanines provide optical limiting properties for photonic devices to control light frequency and intensity in a predictable manner. The optical limit of CNTs composites is saturated at CNTs exceeding 3.8wt% relative to the polymer mass (Chen et al., 2002). Polymer/ CNT composites could also be used to protect human eyes, for example, optical elements, optical sensors, and optical switching (Cao et al., 2002). 

The most widely employed material characterization techniques in third-order nonlinear optics are third-harmonic generation (THG) [21], degenerate four wave-mixing (DFWM) [22], Z-scan [6], and optical limiting by direct two-photon absorption (TPA) and fluorescence spectroscopy induced by TPA [23]. All of them will be discussed in the following. Further measurement techniques such as electric-field induced second-harmonic generation (EFISH) [24], optical Kerr... 

The reflectivity and width of the band gaps increase as the refractive index modulation increases. The basic principle for optical limiting by a ID nonlinear photonic crystal material can be understood from Figure 2. Initially, (A), the refractive indices of the different layers are matched, and the sample... 

Polymer-embedded gold nanoparticles have been extensively studied [1]. Because of unique physical characteristics, gold-polymer nanocomposites are potentially useful for a number of advanced functional applications, especially in the optical and photonic fields. In particular, these materials can be used as light-stable color filters [2], polarizers [3, 4], ultra-low refractive index materials [5], nonlinear optical devices [6], optical sensors [7], and so on. However, still limited are the chemical routes that allow us to obtain monodispersed thiol-derivatized gold nanoparticles with controlled size to be embedded into poly-... 

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