Nonreciprocal Properties of Waveguide-Type Mono-Sectional Optical Isolators Using Bi: YIG Thin-Films

Kazunari TAKI  Yasumitsu MIYAZAKI  

IEICE TRANSACTIONS (1976-1990)   Vol.E71   No.2   pp.161-166
Publication Date: 1988/02/25
Online ISSN: 
Print ISSN: 0000-0000
Type of Manuscript: PAPER
Category: Electro-Optics

Full Text: PDF>>
Buy this Article

Nonreciprocal mode conversion properties and isolation ratios have been experimentally investigated for a mono-sectional optical isolator. The unidirectional mode converter of the mono-sectional optical isolator consists of a Bi-substituted YIG single crystal film sputtered on a GGG substrate. The mode converter is uniformly magnetized at angles with respect to both the film normal and the light propagation direction so that the Faraday and the Cotton-Mouton effects simultaneously occur in one mode converter. At the propagation length of 2.4 mm, the maximum isolation ratio of 13.0 dB has been obtained for the magnetic field of 100.2 Oe which tilts by 6.4and 38.8from the film normal and the plane transverse to the light propagation direction, respectively. In order to achieve large isolation, it is important to control the longitudinal magnetic field component. The insertion loss of the mode converter has been estimated to be 5.5 dB.