Wavelength tunable, soliton pulse generation from an integrated DBR laser-modulator

Abstract

The integrated laser-modulator has become a very attractive, compact source for future applications in high bit rate optical communication systems which require single frequency, low chirp performance. Recently, picosecond soliton pulse generation using sinusoidally driven electroabsorption modulators has been reported using both discrete [1,2] and integrated modulators [3,4], This technique provides flexible repetition rate operation and reduced complexity when compared with mode-locked fiber ring lasers or external cavity semiconductor lasers. Additional functionality is attained if the source is wavelength tunable, leading to potential application in wavelength division multiplexed (WDM) systems or single channel systems designed to operate at an optimum wavelength. Integrating a distributed Bragg reflector (DBR) laser with the semiconductor modulator enables electrical wavelength tuning to be achieved [5]. Here, we report an integrated DBR laser and bulk electroabsorption modulator which produces 25 ps transform-limited pulses at a repetition rate of 10 GHz over a 6.5 nm wavelength range near 1.55 μm.