Semiconductor components for femtosecond semiconductor disk lasers grown by MOVPE

Abstract Diode-pumped semiconductor disk lasers (SCDLs), also known as optically-pumped semiconductor vertical-external-cavity surface-emitting lasers (OPS-VECSELs), are promising light sources for achieving high output power in combination with nearly diffraction-limited beam quality as well as for generating short pulses at very high repetition rates. Combining a SCDL gain section with a semiconductor saturable absorber mirror (SAM) and a pump laser diode allows for simple mode-locked all-semiconductor laser designs. The design of these SAM and SCDL gain structures grown by metal-organic vapor phase epitaxy (MOVPE) is presented discussing the different approaches to obtain short pulses. For the SAM structures the common design using an As-implanted and annealed quantum well (QW) was replaced by a structure using a surface-near QW, which caused a significant reduction of the relaxation time. SCDL gain structures with 4–13 QWs and different barrier designs were tested. The shortest pulses were achieved with an asymmetric 4-QW-graded-index barrier design. Pumping this optimized SCDL gain element with an 840 nm laser diode, pulses as short as 290 fs at a repetition rate of 3 GHz and a wavelength of 1036 nm have been obtained.