The invention relates to an optoisolator for use in
fiber-optic communication, which is characterized in that: a positive polarization
state control component, an insulator component and a negative polarization
state control component are parallelly arranged along a
light transmission direction in turn; the positive polarization
state control component is comprised of a first linear
polarizer and a first quarter wave plate, which are parallelly arranged along the
light transmission direction in turn; the
isolator component is comprised of a first high-
reflectivity reflector, a
Faraday rotator, a second high-
reflectivity reflector and a permanent
magnet, which are parallelly arranged along the
light transmission direction in turn; and the negative polarization state control component is comprised of a second quarter wave plate and a second linear
polarizer, which are parallelly arranged along the light transmission direction in turn. The optoisolator has the advantages that: the change in a
Faraday rotation angle does not deteriorate the performance of the optoisolator seriously, so the requirements on the temperature stability of Faraday
magneto-optic materials are lowered; a 40 to 65dB or above isolation degree requirement can be met by simply using single-stage isolation; and light beams do not displace transversely, the light path is short, and the
miniaturization of elements can be realized.