FABRICATION TECHNIQUES AND CHARACTERISTICS OF AL-SIO2 LAMINATED OPTICAL POLARIZERS

This paper investigates techniques for fabricating laminated polarizers (LAMIPOL's), which consist of alternating laminated layers of aluminum and silica, for the wavelength region lambda > 1 mum. The oxidation of Al films is prevented by a suitable choice of deposition conditions. The surfaces of SiO2 films are smoothed by bias sputtering. A 10 mum thick LAMIPOL was obtained having an insertion loss of 0.15 dB and an extinction ratio of greater than 60 dB at the wavelength of 1.3 mum. These characteristics can be estimated from the attenuated constants of the fundamental modes even when higher modes are considered.