Method for measuring the phase error distribution of a wideband arrayed waveguide grating in the frequency domain.
We describe a method for measuring the phase error distribution of an arrayed waveguide grating (AWG) in the frequency domain when the free spectral range (FSR) of the AWG is so wide that it cannot be covered by one tunable laser source. Our method is to sweep the light frequency in the neighborhoods of two successive peaks in the AWG transmission spectrum by using two laser sources with different tuning ranges. The method was confirmed experimentally by applying it to a 160 GHz spaced AWG with a FSR of 11 THz. The variations in the derived phase error data were very small at +/-0.02 rad around the central arrayed waveguides.
Department of Electronic Engineering, Faculty of Engineering, Gunma University, Kiryu, Japan.
Kazumasa
K
Takada
Shin-ichi
S
Satoh