Transient chirp in high speed photonic crystal quantum dots lasers with controlled spontaneous emission

TL;DR

This paper investigates the dynamics of spontaneous emission in photonic crystal quantum dot lasers, demonstrating high-speed modulation and transient chirp control, which are crucial for optical communication applications.

Contribution

It presents experimental results on controlling spontaneous emission and transient chirp in nanolasers with photonic crystal cavities embedding quantum dots, achieving 10 GHz modulation speeds.

Findings

Modulation speeds of ~10 GHz with 19 dB extinction ratio.

Transient wavelength shift of less than 100 pm for 35-ps pulses.

Chirp characteristics are independent of laser repetition rate up to 10 GHz.

Abstract

We report on a series of experiments on the dynamics of spontaneous emission controlled nanolasers. The laser cavity is a photonic crystal slab cavity, embedding self-assembled quantum dots as gain material. The implementation of cavity electrodynamics effects increases significantly the large signal modulation bandwidth, with measured modulation speeds of the order of 10 GHz while keeping an extinction ratio of 19 dB. A linear transient wavelength shift is reported, corresponding to a chirp of less than 100 pm for a 35-ps laser pulse. We observe that the chirp characteristics are independent of the repetition rate of the laser up to 10 GHz.