Résumé
Abstract-Biochemical detection applications and on-chip optical interconnects are examples of the useful applications considered for integrated photonic platforms dedicated to the UV and visible spectral range. This achievement requires the realization of efficient and compact microlaser sources that can be coupled to optical waveguides and are compatible with photonic circuitry. We develop a cost-effective practical approach relying on the controlled growth of thin AlN buffer layers on silicon substrates, followed by the growth of multiple quantum wells (MQW) GaN/AlN (for UV operation), or InGaN/GaN MQWs (for violet and blue operation) with a high radiative efficiency up to T=300K. This unique Nitride-on-Silicon platform could be released into a membrane by the selective under-etching of the silicon substrate.We present a series of microdisk lasers operating at room temperature under pulsed optical excitation over a broad spectral range extending from 275nm to 470nm. All microdisks present a Q factor above 1000 and reach 4000 in the best resonators. We are able to investigate the gain threshold of the different active layers. The microlasers operate under pulsed optical excitation, and the lasing threshold is reduced by a factor 10 from deep-UV GaN/AlN microdisks to the violet InGaN/GaN ones. This work allows us to expect a variety of integrated photonics applications, including for example multi-color integrated laser sources: we demonstrate here the versatility of this nitride-on-silicon platform, and the first realization on this platform of efficient active layers for a tunable lasing action over a 200nm broad UV to visible spectral range. [1,2].Acknowledgements: The authors acknowledge support from the projects GANEX (ANR-11-LABX-0014) and QUANONIC (ANR-13-BS10-0010). GANEX belongs to the public funded 'Investissements d'Avenir' program managed by the French ANR agency. This work was also partly supported by the RENATECH network.REFERENCES1.Sellés et al., APL 109, 231101 (2016)2.Sci. Rep. 6, 21650 (2016)