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Optically activated switch/modulator using a photoconductor and two channel waveguides
Author(s) -
Goldberg Lew,
Lee Sing H.
Publication year - 1977
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs012i004p00537
Subject(s) - waveguide , materials science , optoelectronics , optical modulator , optics , optical switch , signal (programming language) , electrode , modulation (music) , lithium niobate , physics , phase modulation , computer science , quantum mechanics , phase noise , acoustics , programming language
An optically activated switch was fabricated on LiNbO 3 substrate by deposition of photoconductor‐metal electrode structure on two channel waveguides obtained by the outdiffusion process. One waveguide was overcoated with a CdS film, and served as a light detector which converted the optical signal in that waveguide into an electrical signal. Utilizing the electrooptic effect, this electrical signal modulated the light propagating in the second waveguide by changing the refractive index, and the cutoff condition, of the waveguiding channel between two metal electrodes. (The second waveguide and associated electrodes constituted an electrically activated electrooptic modulator.) The waveguides in the optically controlled switch can be either single or multimode. The length of the device can be short in comparison with other switching schemes. When binary optical signals are applied to the two waveguides, the switch can perform logic AND, NEGATION, OR and pseudo‐amplification operations.