Multi-channel modulation in a DWDM monolithic photonic integrated circuit

We present a multi-channel modulation circuit monolithically integrated with one 25-GHz-spacing AWG for both MUX and DEMUX and eight channels of SOAs and EAMs. The circuit can generate individual optical signals for each DWDM channel with a high extinction ratio of >20 dB and loss compensation. The circuit size can be reduced to 15 /spl times/ 7 mm/sup 2/.

I. Introduction

Wavelength division multiplexing (WDM) transmission networks route optical channels by their corresponding wavelengths. In advanced WDM systems, large numbers of wavelength channels with narrow spacing, called dense-WDM (DWDM), are needed according to the increase of wavelength paths to allocate, and a multi-wavelength optical source, such as a mode-locked laser diode, will be very attractive because this provides simultaneous multi-wavelength lasing and precise wavelength tuning. Such an optical source essentially requires a compact and high-speed multi-channel modulation component that can individually modulate the DWDM lights generated from it.