A Monolithic Wideband Wavelength-Tunable Laser Diode Integrated With a Ring/MZI Loop Filter

We propose a widely tunable and low insertion loss loop filter incorporating two ring resonators and an asymmetric Mach-Zehnder interferometer. A semiconductor optical amplifier, phase control section, and loop filter are monolithically integrated on one chip in the InP-InGaAsP material system. The tuning range of 39 nm with side-mode suppression ratio of over 30 dB was demonstrated. The maximum of the total heater power over the tuning range was 84 mW.