Directional control of optical power in integrated InP/InGaAsP extended cavity mode-locked ring lasers

We report on a passively mode-locked InP/InGaAsP multiple quantum well semiconductor ring laser that operates at a 20 GHz repetition rate and around 1575nm wavelength. The device has been realized using the active-passive integration technology in a standardized photonic integration platform. We demonstrate experimentally for the first time to our knowledge that the relative positioning of the amplifier and absorber in a monolithically integrated ring laser can be used to control the balance of power between counterpropagating fields in the mode-locked state. The directional power balance is verified to be in agreement with a model previously reported. (C) 2011 Optical Society of America