One of the unique properties of lasers is the reduced spectral distribution of their optical emission as compared to other light sources. This laser ’linewidth’ relates to the statistical notion of ’coherence’ and it is inversely proportional to the distance (or time) over which the electromagnetic wave remains with a deterministic phase. In the Group of Integrated Photonics, we currently explore a new type of laser, both theoretically and experimentally. It aims at a laser package with sub-kHz linewidth, side-mode suppression ratio (SMSR) higher than 40 dB, output power in excess of 10 mW with a wavelength tunable over 10 nm around 1550 nm. This is driven for coherent communication, where the involved higher-order modulation formats require a narrow laser linewidth. The form factor, the reliability and the cost of the laser package are also critical for these systems. This motivates to adopt a fabless approach, where mature material systems (e.g. based on InP) are available in commercial semiconductor foundries. Other applications that will benefit from this narrow-linewidth lasers include dual-comb spectroscopy, frequency synthesis, ultraprecise timing, and also more fundamentally, the study of nonlinear optical phenomena generated on a chip.

This is an on-going project. Please have a look at this press release or contact us if you would like to know more about it.