Thermally stable hybrid cavity laser based on silicon nitride gratings

S Iadanza; A P Bakoz; P K J Singaravelu; D Panettieri; S A Schulz; G C R Devarapu; S Guerber; C Baudot; F Boeuf; S Hegarty; L O'Faolain

doi:10.1364/AO.57.00E218

Thermally stable hybrid cavity laser based on silicon nitride gratings

Appl Opt. 2018 Aug 1;57(22):E218-E223. doi: 10.1364/AO.57.00E218.

Authors

S Iadanza, A P Bakoz, P K J Singaravelu, D Panettieri, S A Schulz, G C R Devarapu, S Guerber, C Baudot, F Boeuf, S Hegarty, L O'Faolain

PMID: 30117905
DOI: 10.1364/AO.57.00E218

Abstract

In this paper, we show the experimental results of a thermally stable Si₃N₄ external cavity (SiN EC) laser with high power output and the lowest SiN EC laser threshold to our knowledge. The device consists of a 250 μm sized reflective semiconductor optical amplifier butt-coupled to a passive chip based on a series of Si₃N₄ Bragg gratings acting as narrow reflectors. A threshold of 12 mA has been achieved, with a typical side-mode suppression ratio of 45 dB and measured power output higher than 3 mW. Furthermore, we achieved a mode-hop free-lasing regime in the range of 15-62 mA and wavelength thermal stability up to 80°C. This solves the challenges related to cavity resonances' thermal shift and shows the possibility for this device to be integrated in dense wavelength-division multiplexing (WDM) and heat-intensive optical interconnects technologies.