Optical amplitude and phase modulator

Abstract

Abstract PURPOSE:To improve frequency utilization efficiency greatly by imposing optical amplitude phase modulation wherein amplitude modulation and phase modulation are performed simultaneously. CONSTITUTION:An amplitude modulation part 2 composed of a Y-branch type interference optical modulator imposes binary amplitude modulation upon input light 1 firstly. At this time, the branch ratio of an input-side Y branch 3 is set to a 1:(2-3<1/2>) amplitude ratio and branch angles of output-side Y branches 3 and 4 are adjusted. Then, an electrode 7 is added to a waveguide 5 which is smaller in the quantity of branch light between the 1st and the 2nd waveguides 5 and 6 branched at the Y branch 3, and the light shift in phase by pi with a voltage applied to the electrode 7. The composite wave output at the branch 4 varies with the voltage applied to the electrode 7. Here, a phase modulation part 8 imposes binary phase modulation on output light by applying a phase modulating electrode 9 with a voltage which makes a pi shift.

Inventors

• 👤 Katsumi Emura
• 👤 克己 江村
• 👤 Yoshiro Komatsu
• 👤 啓郎 小松

Bibliographic Details