METHOD FOR CONTROLLING OPTICAL MODULATION SYSTEM, OPTICAL MODULATION SYSTEM AND OPTICAL BODY USED THEREIN
Disclosed is a device capable of switching at high speed right circularly polarised light and left circularly polarised light (sign of the rotation ellipticity), that is small and that can be driven with low power, and that is suited to writing on recording media. An optical body is provided in which there are laminated: a first reflective layer (12)
a magneto-optical material layer (13)
a variable refractive index layer (14) sandwiched by transparent electrodes
and a second reflective layer (15) provided on a transparent substrate. In addition, a refractive index control section is provided which is capable of controlling the refractive index of the variable refractive index layer (14) to a first refractive index or a second refractive index. This refractive index control section makes the second light (output light) electrically polarised light in the first direction in the case of the first refractive index and makes the second light electrically polarised light in the second direction in the case of the second refractive index.