Realisation of flat FM response by directly modulating a phase tunable DFB laser diode

Abstract

Flat and efficient FM responses in a wide frequency range were obtained by directly modulating the injection current of a 1.3 μm phase-tunable DFB-DC-PBH laser diode. The FM response is flat between 1 kHz and 300 MHz, and the nor malised frequency deviation is 1–3 GHz/mA, which is 5–10 times larger than that of a conventional laser diode in the several hundred megahertz region.