A hybrid single or multi-wavelength laser using an optical gain element, such as a semiconductor optical amplifier (SOA), for example a QD RSOA, and a semiconductor, e.g. silicon, photonics chip is demonstrated. A plurality, e.g. four, lasing modes at a predetermined, e.g. 2 nm, spacing and less than 3 dB power non-uniformity may be observed, with over 20 mW of total output power. Each lasing peak can be successfully modulated at 10 Gb/s. At 10−9 BER, the receiver power penalty is less than 2.6 dB compared to a conventional commercial laser. An expected application is the provision of a comb laser source for WDM transmission in optical interconnection systems.