TUTCRIS - Tampereen teknillinen yliopisto


MECSELs with direct emission in the 760 nm to 810 nm spectral range: A single- and double-side pumping comparison and high-power continuous-wave operation



OtsikkoVertical External Cavity Surface Emitting Lasers (VECSELs) IX
ToimittajatUrsula Keller
KustantajaSPIE, IEEE
ISBN (elektroninen)9781510624443
DOI - pysyväislinkit
TilaJulkaistu - 2019
OKM-julkaisutyyppiA4 Artikkeli konferenssijulkaisussa
TapahtumaVertical External Cavity Surface Emitting Lasers - San Francisco, Yhdysvallat
Kesto: 5 helmikuuta 20196 helmikuuta 2019


NimiProceedings of SPIE - The International Society for Optical Engineering
ISSN (painettu)0277-786X
ISSN (elektroninen)1996-756X


ConferenceVertical External Cavity Surface Emitting Lasers
KaupunkiSan Francisco


We compared single-side pumping (SSP) and double-side pumping (DSP) of a semiconductor membrane external-cavity surface-emitting laser (MECSEL). The MECSEL's active region was based on a 4×3 AlGaAs quantum well (QW) structure. This structure was embedded between two silicon carbide (SiC) wafer pieces that were used as transparent intra-cavity (IC) heat spreaders creating a symmetrical cooling environment. The MECSEL structure targeted emission at 780nm and was operated at 20°C heat sink temperature. Via DSP the differential efficiency was improved from 31.9% to 34.4 %. The laser threshold was reduced from 0.79 W to 0.69 W of absorbed pump power while the maximum output power was increased from 3.13 W to 3.22 W. The DSP configuration enabled these improvements by a reduced thermal resistance of the gain element by 9 %. The MECSEL operated at a fundamental Gaussian TEM00 mode profile and the beam quality was measured to be M2 <1.09. We further demonstrate a maximum tuning range from 767 nm to 811 nm. A similar active region with about half the thickness (2×3 AlGaAs QWs) was investigated using the DSP configuration and first results are presented here. 500-μm-thick sapphire IC heat spreaders were used instead of SiC. The output power exceeded 0.5W and the emission was spectrally located around 770 nm.