Patent
1989-03-31
1991-01-29
Arnold, Bruce Y.
350403, 350405, G02F 109, G02B 530, G02B 2728
Patent
active
049881701
ABSTRACT:
A quasi-achromatic configuration of two Faraday elements and five birefringent plates which when suitably oriented between two linearly polarizing elements would constitute an optical isolator or circulator. The nominal Faraday rotations of the two elements are 45.degree. and 90.degree. at a center design wavelength about which the devices are to operate. Changes in these rotations due to either wavelength or temperature variations compensate one another because of their coupling by the birefringent plates. In this way a higher degree of isolation is obtained over a wider optical bandwidth than would be possible in a device using a single 45.degree. Faraday element. A group of three plates is used between the two Faraday elements and two more follow them to give the required polarization transformations which must themselves be quasi-achromatic over the desired wavelength range.
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Arnold Bruce Y.
GTE Laboratories Incorporated
Lohmann, III Victor F.
Parsons David R.
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