Abstract
We present a comparison of epitaxial designs for barrier pumped vertical external-cavity surface-emitting lasers in the red spectral range. The VECSEL chips are grown by metal-organic vapor-phase epitaxy as GaInP/AlGaInP multi-quantum well structures with 20 and 21 compressively strained quantum wells, respectively. The QWs are placed in various packages in a separate confinement heterostructure with quaternary AlGaInP-barrier and cladding layers. Beneath the active region there is a distributed Bragg reflector consisting of 55 λ/4 pairs of Al0.5Ga0.5As/AlAs. We compare three different QW distributions: one design includes 20 QWs arranged in 10 pairs, the second one contains 20 QWs arranged in 10 pairs with tensile strained barriers to compensate the compressive strain of the QWs, the third one has an exponential distribution of the QWs in tensile strained barriers. Laser parameters such as wavelength, differential efficiency, optical output power and absorption of the pump laser were measured for the different designs. By using the exponential distribution of QWs we could improve the differential efficiency by 42% and the output power by 20% compared to the not strain compensated 10×2 QW design. Furthermore we could improve the absorption efficiency by 60% at nearly the same laser wavelength.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
