InAs/InP quantum dot VECSEL emitting at 1.5 μm

Abstract

A high-power InAs quantum dot (QD) vertical-external-cavity surface-emitting laser emitting at 1.5 μm is reported. The active region employs 20 layers of high-density Stranski–Krastanow InAs quantum dots on an InP substrate. The QD density and emission wavelength were independently adjusted by employing a double-cap growth sequence. Optimization of the spacer layer thickness and strain compensation rendered possible nucleation of a relatively high number of QD layers per antinode of the electromagnetic standing wave, which in turn enabled a high output power continuous wave operation of about 2.2 W. The operation wavelength could be tuned over 60 nm, taking advantage of the broadband gain characteristic of QD media.

Quantum dot membrane external-cavity surface-emitting laser at 1.5 μm

“…The broader tuning range of 86 nm was achievable with a high-reflecting R M3 > 99.8 % outcoupling mirror. Compared to earlier 1.5 μm VECSELs 21,22 , the highest tuning range has been achieved at the 1.5 μm wavelength band here in this work. The polarization behavior of the QD MECSEL was analyzed without any intra cavity elements inside a linear cavity to avoid any preferred polarization that would be given by a V-cavity.…”

“…The antinode between these two QD layers is practically left out, such that each QDs group is carefully positioned at stationary field antinodes. Details of the QD fabrication by the Stranski-Krastanow growth mode, the gain structure and its laser performance as a VECSEL at 14 • C employing intra cavity diamond heat spreaders have been described elsewhere 22 . After the growth was completed, the substrate was mechanically thinned before being removed wet-chemically with an HCl solution.…”

“…Alternative demonstrations involving GaInAsN/GaAs QWs and AlAs/GaAs DBR pairs grown on GaAs, have also resulted in rather low output power in the 80 mW range 19 . An alternative solution to the monolithic approach is to grow the InP-based active structure and the AlAs/GaAs DBR separately on two different types of substrates, and afterwards combining them via wafer-fusion [20][21][22] . This involves a higher level of complexity.…”

High-Power 760 nm VECSEL Based on Quantum Dot Gain Mirror

“…The QD gain mirror structure is comprised of an InP-based active region employing InAs QDs wafer fused to a GaAsbased GaAs/AlAs DBR. Complete characterization details for fundamental operation are provided in [13] (including PL measurements). Intracavity heatspreader thermal management scheme was employed by utilizing an uncoated diamond with a thickness of 0.3 mm.…”

“…Despite these notable achievements, the state-ofthe-art AlGaAs-based direct emitting structures possess a set of drawbacks, namely, low laser lifetime, and polarization peculiarities degrading the output beam at high power [11]. In this Letter, we report second-harmonic generation (SHG) based on new type of gain mirrors recently proposed for emission at 1550 nm [13]. In particular, we demonstrate ~1.2 W of output power at the 760 nm from intracavity frequency conversion of QD-based VECSEL.…”