Metallic thin-film/polymer "sandwich" acts as modulator

An optical modulator made of thin-film electro-optic polymer sandwiched between silver thin-film contacts on a glass substrate was assembled by a grou¥at the University of Washington (UW, Seattle, WA). The device is capable of modulation as a function of the polymer refractive index. The UW device consists of a 250-nm silver thin film ato¥a 3.3-µm-thick polymer layer, deposited on a 51.2-nm silver bottom layer that has been evaporated onto a transparent leaded-glass substrate.The ind

Metallic thin-film/polymer "sandwich" acts as modulator

An optical modulator made of thin-film electro-optic polymer sandwiched between silver thin-film contacts on a glass substrate was assembled by a grou¥at the University of Washington (UW, Seattle, WA). The device is capable of modulation as a function of the polymer refractive index. The UW device consists of a 250-nm silver thin film ato¥a 3.3-µm-thick polymer layer, deposited on a 51.2-nm silver bottom layer that has been evaporated onto a transparent leaded-glass substrate.The index of refraction, n, was modulated from 1.72 to 1.74 by an applied voltage in a 50:50 mixture of P2ANS/MMA polymer (Hoechst Celanese). The grou¥obtained linear modulation of approximately 70% over this range, with full absorption of the incident beam occurring at n = 1.72. These experiments were performed with a 632.8-nm HeNe laser, but researchers Chuck Jung, Sinclair Yee, and Kelin Kuhn have begun work on a device optimized for 1.3-µm wavelengths. For more on modulators, see p. 135.

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