In-line phase modulators using coaxial thick lead zirconate titanate coated optical fibers

Thick piezoelectric lead zirconate titanate (PZT) films (ceramic–ceramic 0–3 composite films), using a new sol-gel based process, have been produced and used to coaxially coat optical fibers. Coated PZT of up to 200 μm thick and 10 cm long have been achieved. Using thick PZT coated single mode optical fibers, in-line phase modulators are designed, built and tested. Theoretical and experimental investigations of such phase modulators are also presented. The measured phase modulation ranges from hundreds of kilohertz to several megahertz.