Furukawa Electric Review No.48 Telecommunication・EnergyA Narrow Linewidth Tunable Light Source with an Etched Core DR Laser

Kazuaki Kiyota, Go Kobayashi, Shunsuke Okuyama, Tatsuya Kimoto

A narrow spectral linewidth is required for both the signal light source and the local oscillator light source in a digital coherent communication. The use of a DR laser with a combination of a conventional Distributed Feedback (DFB) laser and a Distributed Bragg Reflector (DBR) mirror shows promise for improving the characteristic of the spectral linewidth. We devised a configuration employing an etched core type DBR for a DR laser, where an active layer as a waveguide core is periodically etched. We have achieved a linewidth of less than 150 kHz by applying this etched core type DR laser to the laser part of a wide wavelength tunable light source.