A Directly Modulated Multiwavelength Transmitter Monolithically Integrated on InP

This paper presents an integrated multiwavelength transmitter with eight channels realized on a generic InP integration platform. The photonic integrated circuit (PIC) comprises eight tunable directly modulated distributed feedback lasers emitting in the C-band, eight monitoring photodetectors, and MMI couplers. The PIC has been mounted on a printed circuit board for easier operation and wavelength control. The directly modulated lasers, designed with a 100 GHz spacing between 1541.4 and 1547 nm, show a 3-dB bandwidth up to 12 GHz and a tunability range of about 4 nm. Transmission experiments demonstrate error-free operation in back-to-back and open eye-diagrams up to 20 Gb/s per channel, while short-range communications (along a 2.1 km fiber span) up to 15 Gb/s per channel incur in a limited power penalty (4.5 dB at a bit error rate = 10-9).