| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical waveplate which is less expensive and is manufactured more easily than a polyimide waveplate, while retaining performance comparable to that of the polyimide waveplate and substitutes for the polyimide waveplate. SOLUTION: The optical waveplate is manufactured from a polyethylene naphthalate(PEN). The polyethylene naphthalate waveplate 3 has various optical characteristics, comparable to or higher than those of a waveplate manufactured from a polyimide (PI) by prior art. The PEN waveplate 3 is a technically, and commercially valid alternative for the PI waveplate. The PEN waveplate 3 is disposed in a slot 4 between lightguides 1, 2 formed on a silicon substrate 5 and it is disposed at about 85 deg. angle with respect to the optical axes of the lightguides 1, 2 so as to prevent backward reflection. The PEN waveplate 3 has a film shape and the thickness is in the range of 2 to about 25μm. |
