Narrow Linewidth Semiconductor Disk Lasers and Progress Towards ZnCdMgSe Vertical Gain Structures

Description

Optically-pumped semiconductor disk lasers (SDLs), also commonly known as vertical external cavity surface-emitting lasers (VECSELs), are of particular interest for applications that require high spatial and/or spectral brightness at novel wavelengths. A typical SDL gain structure consists of a multi-quantum-well resonant periodic gain region on a monolithic distributed Bragg reflector (DBR). This gain mirror is then optically-pumped and aligned within a conventional air-spaced laser resonator. With their relatively high output power (multi-Watt) and high finesse cavities, SDLs are ideally suited for narrow linewidth operation, demonstrating low frequency and intensity noise; properties we are currently exploiting to develop visible SDLs with sub-kHz linewidth for application in quantum technology, specifically atomic clocks. SDLs have been demonstrated from the deep ultraviolet to the mid-infrared via a combination of III-V semiconductor bandgap engineering and intracavity nonlinear frequency conversion; however, direct emission at wavelengths around the so-called ‘green-gap’ would offer many advantages in size, efficiency, and tunability as well as removing a nonlinear conversion step towards the UV. With the advent of high power GaN pump lasers, un-doped II-VI materials show promise for optically-pumped gain structures in this spectral region, and there is already a large body of work on II-VI-based vertical structures on GaAs, including high quality DBRs. Our interest is in ZnMgCdSe on InP substrates, which offers optical gain from the blue to the red. Optically-pumped edge-emitting lasers in the blue, green, and red were previously demonstrated by the Tamargo group. DBRs are in development with the possibility of using the superlattice technique that has proved successful for material lattice-matched to GaAs; however, SDLs need not have a monolithic DBR if the quantum well gain region can be transferred to a transparent substrate. Here we present an overview of our recent work in visible narrow linewidth SDLs, and our progress on the design, growth, processing and characterization of ZnCdMgSe multi-quantum well vertical gain structures, including transfer of gain regions to single crystal diamond windows.

Period	24 Apr 2019
Event title	MRS Spring Meeting 2019
Event type	Conference
Location	Phoenix, United StatesShow on map
Degree of Recognition	International