| 摘要 |
PURPOSE:To raise the Faraday effect, and also, to prevent the modulation efficiency from dropping even if length of a fiber is lengthened, by constituting a core, or the core and a clad of oxide glass containing Pr, Tb, Dy, Ce, and Ho, whose Verdet constant is large. CONSTITUTION:A core of a constant polarized wave signal mode fiber is constituted of oxide glass containing at least one kind which has been selected from Pr, Tb, Dy, Ce, and Ho. Also, it is allowed that not only the core but also a clad are constituted of oxide glass containing at least one kind which has been selected from Pr, Tb, Dy, Ce and Ho. This constants polarized wave single mode fiber 1 transmits an incident light beam beams of arbitrary plane of polarization, in a state its plane of polarization has been held, and when the constant polarized wave single mode fiber is wound in a shape of a coil so that no 'torsion' is generated, an absolute single polarized wave transmitted through only some plane of polarization is obtained. In this way, a modulator which does not require a polarizer 2 nor an analyzer 3 can be formed. |
